Do we need Hadith to judge?

One common argument made for justification for the upholding of Hadith besides the Quran is that it was the messenger’s job to judge, and it is the duty of the believers to obey his judgment. Some of the strongest verses in the Quran used to attempt to justify these points can be found in the following two verses.

[4:65] Never indeed, by your Lord; they are not believers unless they come to you to judge in their disputes, then find no hesitation in their hearts whatsoever in accepting your judgment. They must submit a total submission.

فَلَا وَرَبِّكَ لَا يُؤْمِنُونَ حَتَّىٰ يُحَكِّمُوكَ فِيمَا شَجَرَ بَيْنَهُمْ ثُمَّ لَا يَجِدُوا۟ فِىٓ أَنفُسِهِمْ حَرَجًا مِّمَّا قَضَيْتَ وَيُسَلِّمُوا۟ تَسْلِيمًا

[33:36] No believing man or believing woman, if GOD and His messenger issue any command, has any choice regarding that command. Anyone who disobeys GOD and His messenger has gone far astray.

وَمَا كَانَ لِمُؤْمِنٍ وَلَا مُؤْمِنَةٍ إِذَا قَضَى ٱللَّهُ وَرَسُولُهُۥٓ أَمْرًا أَن يَكُونَ لَهُمُ ٱلْخِيَرَةُ مِنْ أَمْرِهِمْ وَمَن يَعْصِ ٱللَّهَ وَرَسُولَهُۥ فَقَدْ ضَلَّ ضَلَـٰلًا مُّبِينًا

The error made in thinking these verses support the upholding of Hadith besides the Quran can be understood by asking, “By what mechanism did the messenger judge?” Or put another way, did the messenger judge by the Book of God, or did he judge by some other means that is not contained in the Book of God?

THE FUNCTION OF A JUDGE

Before diving into this question, it is worth pointing out that it is not the function of a judge to make laws but only to interpret and apply them. This means judges are bound by the laws passed by legislative bodies and can only apply those laws to the cases brought before them. Legislators, not judges, are responsible for creating and passing laws.

In the case of religion, God alone is the Lawgiver. He is the One who creates the laws, and it is the messengers’ role to apply the laws given by God as they are commanded.

MESSENGER’S JUDGMENT BY HADITH

If we consult the Hadith literature, we see that it implies that the messenger not only judged but was also in a position to establish laws.

In one narration from Sahih Muslim, the prophet contemplated prohibiting cohabitation.

Judaima daughter of Wahb al-Asadiyya (Allah be pleased with her) reported that she heard Allah’s Messenger (ﷺ) as saying: I intended to prohibit cohabitation with a suckling woman until I considered that the Romans and the Persians do it without any injury being caused to their children thereby. (Imam Muslim said: Khalaf reported it from Judamat al-‘Asadiyya, but the correct wording is what has been stated by Yahya.)

وَحَدَّثَنَا خَلَفُ بْنُ هِشَامٍ، حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، ح وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، – وَاللَّفْظُ لَهُ – قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ نَوْفَلٍ عَنْ عُرْوَةَ عَنْ عَائِشَةَ عَنْ جُدَامَةَ بِنْتِ وَهْبٍ الأَسَدِيَّةِ أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ “‏ لَقَدْ هَمَمْتُ أَنْ أَنْهَى عَنِ الْغِيلَةِ حَتَّى ذَكَرْتُ أَنَّ الرُّومَ وَفَارِسَ يَصْنَعُونَ ذَلِكَ فَلاَ يَضُرُّ أَوْلاَدَهُمْ ‏”‏ ‏.‏ قَالَ مُسْلِمٌ وَأَمَّا خَلَفٌ فَقَالَ عَنْ جُذَامَةَ الأَسَدِيَّةِ ‏.‏ وَالصَّحِيحُ مَا قَالَهُ يَحْيَى بِالدَّالِ ‏.‏

Sahih Muslim 1442a https://sunnah.com/muslim:1442a

In another narration Bukhari claims the prophet considered making Siwak mandatory for ablution.

Narrated Abu Huraira: Allah’s Messenger (ﷺ) said, “If I had not found it hard for my followers or the people, I would have ordered them to clean their teeth with Siwak for every prayer.”

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ “‏ لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي ـ أَوْ عَلَى النَّاسِ ـ لأَمَرْتُهُمْ بِالسِّوَاكِ مَعَ كُلِّ صَلاَةٍ ‏”‏‏.‏

Sahih al-Bukhari 887 https://sunnah.com/bukhari:887

In a third example, Abu Dawud claims that the messenger restricted cupping and perpetual fasting but didn’t make them unlawful because he wanted to show mercy to his companions.

Narrated ‘Abd al-Rahman b. Abi Laila: A man from the Companions of the Prophet (ﷺ) told me that the Messenger of Allah (ﷺ) restricted cupping and perpetual fasting, but he had not made them unlawful showing mercy on his Companions. Thereupon he was asked: Messenger of Allah, you observe perpetual fast till dawn. He replied: I observe perpetual fast till dawn (for) my Lord gives me food and drink.

حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، عَنْ سُفْيَانَ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَابِسٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى، حَدَّثَنِي رَجُلٌ، مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنِ الْحِجَامَةِ وَالْمُوَاصَلَةِ وَلَمْ يُحَرِّمْهُمَا إِبْقَاءً عَلَى أَصْحَابِهِ فَقِيلَ لَهُ يَا رَسُولَ اللَّهِ إِنَّكَ تُوَاصِلُ إِلَى السَّحَرِ ‏.‏ فَقَالَ ‏ “‏ إِنِّي أُوَاصِلُ إِلَى السَّحَرِ وَرَبِّي يُطْعِمُنِي وَيَسْقِينِي ‏”‏ ‏.‏

Sunan Abi Dawud 2374 https://sunnah.com/abudawud:2374

To assume that the prophet had the authority to make such commandments directly contradicts the Quran. The Quran informs us that the prophet was enjoined from being able to issue any prohibitions that were not authorized by God. So, it doesn’t make sense to think that he was considering such prohibitions for his people, let alone that he even had the authority to do so.

[66:1] O you prophet, why do you prohibit what GOD has made lawful for you, just to please your wives? GOD is Forgiver, Merciful.

يَـٰٓأَيُّهَا ٱلنَّبِىُّ لِمَ تُحَرِّمُ مَآ أَحَلَّ ٱللَّهُ لَكَ تَبْتَغِى مَرْضَاتَ أَزْوَٰجِكَ وَٱللَّهُ غَفُورٌ رَّحِيمٌ

We have another example below regarding the commandment from God for the prophet to marry the divorced wife of his adopted son. If the prophet was allowed to determine what was lawful or unlawful based on his discretion, he wouldn’t have been called out for being apprehensive about carrying out God’s decree. Note that this verse comes immediately after the command, emphasizing that if one wants to be in the fold of the religion, one must obey God and His messenger.

[33:36] No believing man or believing woman, if GOD and His messenger issue any command, has any choice regarding that command. Anyone who disobeys GOD and His messenger has gone far astray.

وَمَا كَانَ لِمُؤْمِنٍ وَلَا مُؤْمِنَةٍ إِذَا قَضَى ٱللَّهُ وَرَسُولُهُۥٓ أَمْرًا أَن يَكُونَ لَهُمُ ٱلْخِيَرَةُ مِنْ أَمْرِهِمْ وَمَن يَعْصِ ٱللَّهَ وَرَسُولَهُۥ فَقَدْ ضَلَّ ضَلَـٰلًا مُّبِينًا

[33:37] Recall that you said to the one who was blessed by GOD, and blessed by you, “Keep your wife and reverence GOD,” and you hid inside yourself what GOD wished to proclaim. Thus, you feared the people, when you were supposed to fear only GOD. When Zeid was completely through with his wife, we had you marry her, in order to establish the precedent that a man can marry the divorced wife of his adopted son. GOD’s commands shall be done.

وَإِذْ تَقُولُ لِلَّذِىٓ أَنْعَمَ ٱللَّهُ عَلَيْهِ وَأَنْعَمْتَ عَلَيْهِ أَمْسِكْ عَلَيْكَ زَوْجَكَ وَٱتَّقِ ٱللَّهَ وَتُخْفِى فِى نَفْسِكَ مَا ٱللَّهُ مُبْدِيهِ وَتَخْشَى ٱلنَّاسَ وَٱللَّهُ أَحَقُّ أَن تَخْشَىٰهُ فَلَمَّا قَضَىٰ زَيْدٌ مِّنْهَا وَطَرًا زَوَّجْنَـٰكَهَا لِكَىْ لَا يَكُونَ عَلَى ٱلْمُؤْمِنِينَ حَرَجٌ فِىٓ أَزْوَٰجِ أَدْعِيَآئِهِمْ إِذَا قَضَوْا۟ مِنْهُنَّ وَطَرًا وَكَانَ أَمْرُ ٱللَّهِ مَفْعُولًا

Additionally, if the prophet attributed anything to God that was other than the revelation of God, he would have been put to death by God and would have been severely punished.

[69:43] A revelation (Tanzil) from the Lord of the universe. [69:44] And if he fabricated against us other words. [69:45] We would have seized him by his right hand. [69:46] Then we would have severed the aorta from him. [69:47] None of you could have helped him.

تَنزِيلٌ مِّن رَّبِّ ٱلْعَـٰلَمِينَ وَلَوْ تَقَوَّلَ عَلَيْنَا بَعْضَ ٱلْأَقَاوِيلِ لَأَخَذْنَا مِنْهُ بِٱلْيَمِينِ ثُمَّ لَقَطَعْنَا مِنْهُ ٱلْوَتِينَ فَمَا مِنكُم مِّنْ أَحَدٍ عَنْهُ حَـٰجِزِينَ

MESSENGERS JUDGE BY THE TRUTH

The Quran clearly states that messengers are prohibited from judging by their opinions. The Quran cites the example of David when he judged between the two brothers and their sheep and was warned against following his own personal opinion in his judgments.

[38:26] O David, we have made you a ruler on earth. Therefore, you shall judge between the people truthfully, and do not follow your personal opinion, lest it diverts you from the way of GOD. Surely, those who stray off the way of GOD incur severe retribution for forgetting the Day of Reckoning.

يَـٰدَاوُۥدُ إِنَّا جَعَلْنَـٰكَ خَلِيفَةً فِى ٱلْأَرْضِ فَٱحْكُم بَيْنَ ٱلنَّاسِ بِٱلْحَقِّ وَلَا تَتَّبِعِ ٱلْهَوَىٰ فَيُضِلَّكَ عَن سَبِيلِ ٱللَّهِ إِنَّ ٱلَّذِينَ يَضِلُّونَ عَن سَبِيلِ ٱللَّهِ لَهُمْ عَذَابٌ شَدِيدٌۢ بِمَا نَسُوا۟ يَوْمَ ٱلْحِسَابِ

1	yādāwūdu	يَـٰدَاوُۥدُ	O David!
2	innā	إِنَّا	Indeed, we
3	jaʿalnāka	جَعَلْنَـٰكَ	[we] made you
4	khalīfatan	خَلِيفَةً	an alternative / vicegerent / ruler
5	fī	فِى	in
6	l-arḍi	ٱلْأَرْضِ	the earth,
7	fa-uḥ’kum	فَٱحْكُم	so judge
8	bayna	بَيْنَ	between
9	l-nāsi	ٱلنَّاسِ	[the] people
10	bil-ḥaqi	بِٱلْحَقِّ	with the truth (*truthfully / equitably)
11	walā	وَلَا	and (do) not
12	tattabiʿi	تَتَّبِعِ	you follow
13	l-hawā	ٱلْهَوَىٰ	the desire / whim / opinion,
14	fayuḍillaka	فَيُضِلَّكَ	then it will mislead you
15	ʿan	عَن	from
16	sabīli	سَبِيلِ	(the) way
17	l-lahi	ٱللَّهِ	(of) God.

This verse also informs us that the messengers were commanded to judge with the truth.

QURAN IS THE TRUTH

God confirms that the Quran is not only the truth, but no other narration is more truthful than His.

[2:146] Those who received the scripture recognize the truth herein, as they recognize their own children. Yet, some of them conceal the truth, knowingly.

ٱلَّذِينَ ءَاتَيْنَـٰهُمُ ٱلْكِتَـٰبَ يَعْرِفُونَهُۥ كَمَا يَعْرِفُونَ أَبْنَآءَهُمْ وَإِنَّ فَرِيقًا مِّنْهُمْ لَيَكْتُمُونَ ٱلْحَقَّ وَهُمْ يَعْلَمُونَ

[2:147] This is the truth from your Lord; do not harbor any doubt.

ٱلْحَقُّ مِن رَّبِّكَ فَلَا تَكُونَنَّ مِنَ ٱلْمُمْتَرِينَ

1	al-ḥaqu	ٱلْحَقُّ	(This is) the truth
2	min	مِن	from
3	rabbika	رَّبِّكَ	your Lord,
4	falā	فَلَا	so (do) not
5	takūnanna	تَكُونَنَّ	[you all] be
6	mina	مِنَ	among
7	l-mum’tarīna	ٱلْمُمْتَرِينَ	the doubters.

[3:62] Absolutely, this is the narration of the truth. Absolutely, there is no god except GOD. Absolutely, GOD is the Almighty, Most Wise.

إِنَّ هَـٰذَا لَهُوَ ٱلْقَصَصُ ٱلْحَقُّ وَمَا مِنْ إِلَـٰهٍ إِلَّا ٱللَّهُ وَإِنَّ ٱللَّهَ لَهُوَ ٱلْعَزِيزُ ٱلْحَكِيمُ

[4:87] GOD: there is no god except He. He will surely summon you on the Day of Resurrection—the inevitable day. Whose narration (Hadith) is more truthful than GOD’s?

ٱللَّهُ لَآ إِلَـٰهَ إِلَّا هُوَ لَيَجْمَعَنَّكُمْ إِلَىٰ يَوْمِ ٱلْقِيَـٰمَةِ لَا رَيْبَ فِيهِ وَمَنْ أَصْدَقُ مِنَ ٱللَّهِ حَدِيثًا

MESSENGERS JUDGE BY SCRIPTURE

As seen, the messengers were obligated to judge strictly by the truth. The following verses show that the truth they are to judge by is specifically the scripture that they received, and anyone who judges by any other means is committing a falsehood.

[2:213] The people used to be one community when GOD sent the prophets as bearers of good news, as well as warners. He sent down with them the scripture, bearing the truth, to judge among the people in their disputes. Ironically, those who received the scripture were the ones who rejected any new scripture, despite clear proofs given to them. This is due to jealousy on their part. GOD guides those who believe to the truth that is disputed by all others, in accordance with His will. GOD guides whoever wills in a straight path.

كَانَ ٱلنَّاسُ أُمَّةً وَٰحِدَةً فَبَعَثَ ٱللَّهُ ٱلنَّبِيِّـۧنَ مُبَشِّرِينَ وَمُنذِرِينَ وَأَنزَلَ مَعَهُمُ ٱلْكِتَـٰبَ بِٱلْحَقِّ لِيَحْكُمَ بَيْنَ ٱلنَّاسِ فِيمَا ٱخْتَلَفُوا۟ فِيهِ وَمَا ٱخْتَلَفَ فِيهِ إِلَّا ٱلَّذِينَ أُوتُوهُ مِنۢ بَعْدِ مَا جَآءَتْهُمُ ٱلْبَيِّنَـٰتُ بَغْيًۢا بَيْنَهُمْ فَهَدَى ٱللَّهُ ٱلَّذِينَ ءَامَنُوا۟ لِمَا ٱخْتَلَفُوا۟ فِيهِ مِنَ ٱلْحَقِّ بِإِذْنِهِۦ وَٱللَّهُ يَهْدِى مَن يَشَآءُ إِلَىٰ صِرَٰطٍ مُّسْتَقِيمٍ

10	wa-anzala	وَأَنزَلَ	and He sent down
11	maʿahumu	مَعَهُمُ	with them
12	l-kitāba	ٱلْكِتَـٰبَ	the book / scripture
13	bil-ḥaqi	بِٱلْحَقِّ	with the truth
14	liyaḥkuma	لِيَحْكُمَ	that it may judge
15	bayna	بَيْنَ	between
16	l-nāsi	ٱلنَّاسِ	[the] people
17	fīmā	فِيمَا	in what
18	ikh’talafū	ٱخْتَلَفُوا۟	they differed / disputed
19	fīhi	فِيهِ	in it.

[5:44] We have sent down the Torah, containing guidance and light. Judging in accordance with it were the Jewish prophets, as well as the rabbis and the priests, as dictated to them in GOD’s scripture, and as witnessed by them. Therefore, do not reverence human beings; you shall reverence Me instead. And do not trade away My revelations for a cheap price. Those who do not judge in accordance with GOD’s revelations, are the disbelievers.

إِنَّآ أَنزَلْنَا ٱلتَّوْرَىٰةَ فِيهَا هُدًى وَنُورٌ يَحْكُمُ بِهَا ٱلنَّبِيُّونَ ٱلَّذِينَ أَسْلَمُوا۟ لِلَّذِينَ هَادُوا۟ وَٱلرَّبَّـٰنِيُّونَ وَٱلْأَحْبَارُ بِمَا ٱسْتُحْفِظُوا۟ مِن كِتَـٰبِ ٱللَّهِ وَكَانُوا۟ عَلَيْهِ شُهَدَآءَ فَلَا تَخْشَوُا۟ ٱلنَّاسَ وَٱخْشَوْنِ وَلَا تَشْتَرُوا۟ بِـَٔايَـٰتِى ثَمَنًا قَلِيلًا وَمَن لَّمْ يَحْكُم بِمَآ أَنزَلَ ٱللَّهُ فَأُو۟لَـٰٓئِكَ هُمُ ٱلْكَـٰفِرُونَ

33	waman	وَمَن	And whoever
34	lam	لَّمْ	not
35	yaḥkum	يَحْكُم	he judges
36	bimā	بِمَآ	by what
37	anzala	أَنزَلَ	[He] revealed,
38	l-lahu	ٱللَّهُ	God
39	fa-ulāika	فَأُو۟لَـٰٓئِكَ	then those
40	humu	هُمُ	[they] (are)
41	l-kāfirūna	ٱلْكَـٰفِرُونَ	the disbelievers.

[5:45] And we decreed for them in it that: the life for the life, the eye for the eye, the nose for the nose, the ear for the ear, the tooth for the tooth, and an equivalent injury for any injury. If one forfeits what is due to him as a charity, it will atone for his sins. Those who do not judge in accordance with GOD’s revelations are the unjust.

وَكَتَبْنَا عَلَيْهِمْ فِيهَآ أَنَّ ٱلنَّفْسَ بِٱلنَّفْسِ وَٱلْعَيْنَ بِٱلْعَيْنِ وَٱلْأَنفَ بِٱلْأَنفِ وَٱلْأُذُنَ بِٱلْأُذُنِ وَٱلسِّنَّ بِٱلسِّنِّ وَٱلْجُرُوحَ قِصَاصٌ فَمَن تَصَدَّقَ بِهِۦ فَهُوَ كَفَّارَةٌ لَّهُۥ وَمَن لَّمْ يَحْكُم بِمَآ أَنزَلَ ٱللَّهُ فَأُو۟لَـٰٓئِكَ هُمُ ٱلظَّـٰلِمُونَ

[5:46] Subsequent to them, we sent Jesus, the son of Mary, confirming the previous scripture, the Torah. We gave him the Gospel, containing guidance and light, and confirming the previous scriptures, the Torah, and augmenting its guidance and light, and to enlighten the righteous.

وَقَفَّيْنَا عَلَىٰٓ ءَاثَـٰرِهِم بِعِيسَى ٱبْنِ مَرْيَمَ مُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ ٱلتَّوْرَىٰةِ وَءَاتَيْنَـٰهُ ٱلْإِنجِيلَ فِيهِ هُدًى وَنُورٌ وَمُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ ٱلتَّوْرَىٰةِ وَهُدًى وَمَوْعِظَةً لِّلْمُتَّقِينَ

[5:47] The people of the Gospel shall judge in accordance with GOD’s revelations therein. Those who do not judge in accordance with GOD’s revelations are the wicked.

وَلْيَحْكُمْ أَهْلُ ٱلْإِنجِيلِ بِمَآ أَنزَلَ ٱللَّهُ فِيهِ وَمَن لَّمْ يَحْكُم بِمَآ أَنزَلَ ٱللَّهُ فَأُو۟لَـٰٓئِكَ هُمُ ٱلْفَـٰسِقُونَ

MUHAMMAD JUDGED WITH THE QURAN

Muhammad was no different than any other messenger before him and, therefore, also judged by the scripture he received, that of the Quran.

[5:48] Then we revealed to you this scripture, truthfully, confirming previous scriptures, and superseding them. You shall judge among them in accordance with GOD’s revelations, and do not follow their wishes if they differ from the truth that came to you. For each of you, we have decreed laws and different rites. Had GOD willed, He could have made you one congregation. But He thus puts you to the test through the revelations He has given each of you. You shall compete in righteousness. To GOD is your final destiny—all of you—then He will inform you of everything you had disputed.

وَأَنزَلْنَآ إِلَيْكَ ٱلْكِتَـٰبَ بِٱلْحَقِّ مُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ ٱلْكِتَـٰبِ وَمُهَيْمِنًا عَلَيْهِ فَٱحْكُم بَيْنَهُم بِمَآ أَنزَلَ ٱللَّهُ وَلَا تَتَّبِعْ أَهْوَآءَهُمْ عَمَّا جَآءَكَ مِنَ ٱلْحَقِّ لِكُلٍّ جَعَلْنَا مِنكُمْ شِرْعَةً وَمِنْهَاجًا وَلَوْ شَآءَ ٱللَّهُ لَجَعَلَكُمْ أُمَّةً وَٰحِدَةً وَلَـٰكِن لِّيَبْلُوَكُمْ فِى مَآ ءَاتَىٰكُمْ فَٱسْتَبِقُوا۟ ٱلْخَيْرَٰتِ إِلَى ٱللَّهِ مَرْجِعُكُمْ جَمِيعًا فَيُنَبِّئُكُم بِمَا كُنتُمْ فِيهِ تَخْتَلِفُونَ

[5:49] You shall judge among them in accordance with GOD’s revelations to you. Do not follow their wishes, and beware lest they divert you from some of GOD’s revelations to you. If they turn away, then know that GOD wills to punish them for some of their sins. Indeed, many people are wicked.

وَأَنِ ٱحْكُم بَيْنَهُم بِمَآ أَنزَلَ ٱللَّهُ وَلَا تَتَّبِعْ أَهْوَآءَهُمْ وَٱحْذَرْهُمْ أَن يَفْتِنُوكَ عَنۢ بَعْضِ مَآ أَنزَلَ ٱللَّهُ إِلَيْكَ فَإِن تَوَلَّوْا۟ فَٱعْلَمْ أَنَّمَا يُرِيدُ ٱللَّهُ أَن يُصِيبَهُم بِبَعْضِ ذُنُوبِهِمْ وَإِنَّ كَثِيرًا مِّنَ ٱلنَّاسِ لَفَـٰسِقُونَ

[4:105] We have sent down to you the scripture, truthfully, in order to judge among the people in accordance with what GOD has shown you. You shall not side with the betrayers.

إِنَّآ أَنزَلْنَآ إِلَيْكَ ٱلْكِتَـٰبَ بِٱلْحَقِّ لِتَحْكُمَ بَيْنَ ٱلنَّاسِ بِمَآ أَرَىٰكَ ٱللَّهُ وَلَا تَكُن لِّلْخَآئِنِينَ خَصِيمًا

1	innā	إِنَّآ	Indeed, [we]
2	anzalnā	أَنزَلْنَآ	we sent down
3	ilayka	إِلَيْكَ	to you
4	l-kitāba	ٱلْكِتَـٰبَ	the scripture
5	bil-ḥaqi	بِٱلْحَقِّ	with the truth (*truthfully)
6	litaḥkuma	لِتَحْكُمَ	so that you may judge
7	bayna	بَيْنَ	between
8	l-nāsi	ٱلنَّاسِ	the people
9	bimā	بِمَآ	with what
10	arāka	أَرَىٰكَ	[He] showed you
11	l-lahu	ٱللَّهُ	God.

The Quran informs the believers that if they dispute in any matter to refer it to to God and the messenger.

And that the messenger judges by means of the scripture.

HADITH: MUHAMMAD’S JUDGMENT OF JEWS

Additionally, as seen above, Muhammad is commanded to judge only by the Quran that was sent to him and not to deviate from it in his judgment, specifically in regards to judging the people of the previous scriptures. Yet, the Hadith claim that Muhammad judged the Jews by means of their own scripture.

Narrated Abdullah bin Umar: The Jews came to Allah’s Messenger (ﷺ) and told him that a man and a woman from amongst them had committed illegal sexual intercourse. Allah’s Messenger (ﷺ) said to them, “What do you find in the Torah (old Testament) about the legal punishment of Ar-Rajm (stoning)?” They replied, (But) we announce their crime and lash them.” Abdullah bin Salam said, “You are telling a lie; Torah contains the order of Rajm.” They brought and opened the Torah, and one of them solaced his hand on the Verse of Rajm and read the verses preceding and following it. Abdullah bin Salam said to him, “Lift your hand.” When he lifted his hand, the Verse of Rajm was written there. They said, “Muhammad has told the truth; the Torah has the Verse of Rajm. The Prophet (ﷺ) then gave the order that both of them should be stoned to death. (Abdullah bin Umar said, “I saw the man leaning over the woman to shelter her from the stones.”

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكُ بْنُ أَنَسٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ الْيَهُودَ، جَاءُوا إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَذَكَرُوا لَهُ أَنَّ رَجُلاً مِنْهُمْ وَامْرَأَةً زَنَيَا فَقَالَ لَهُمْ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ “‏ مَا تَجِدُونَ فِي التَّوْرَاةِ فِي شَأْنِ الرَّجْمِ ‏”‏‏.‏ فَقَالُوا نَفْضَحُهُمْ وَيُجْلَدُونَ‏.‏ فَقَالَ عَبْدُ اللَّهِ بْنُ سَلاَمٍ كَذَبْتُمْ، إِنَّ فِيهَا الرَّجْمَ‏.‏ فَأَتَوْا بِالتَّوْرَاةِ فَنَشَرُوهَا، فَوَضَعَ أَحَدُهُمْ يَدَهُ عَلَى آيَةِ الرَّجْمِ، فَقَرَأَ مَا قَبْلَهَا وَمَا بَعْدَهَا‏.‏ فَقَالَ لَهُ عَبْدُ اللَّهِ بْنُ سَلاَمٍ ارْفَعْ يَدَكَ‏.‏ فَرَفَعَ يَدَهُ فَإِذَا فِيهَا آيَةُ الرَّجْمِ‏.‏ فَقَالُوا صَدَقَ يَا مُحَمَّدُ، فِيهَا آيَةُ الرَّجْمِ‏.‏ فَأَمَرَ بِهِمَا رَسُولُ اللَّهِ صلى الله عليه وسلم فَرُجِمَا‏.‏ قَالَ عَبْدُ اللَّهِ فَرَأَيْتُ الرَّجُلَ يَجْنَأُ عَلَى الْمَرْأَةِ يَقِيهَا الْحِجَارَةَ‏.‏

Sahih al-Bukhari 3635 https://sunnah.com/bukhari:3635

THE QURAN IS THE BOOK OF LAW (AL-FURQAN)

This is the reason one of the names of the Quran is al-Furqãn ( ٱلْفُرْقَانَ ), The Statute Book. This is because the Quran is the Book of Law, and the only book by which the prophet and the upholders of the Quran are to judge by.

[25:1] Most blessed is the One who revealed the Statute Book to His servant, so he can serve as a warner to the whole world.

تَبَارَكَ ٱلَّذِى نَزَّلَ ٱلْفُرْقَانَ عَلَىٰ عَبْدِهِۦ لِيَكُونَ لِلْعَـٰلَمِينَ نَذِيرًا

The Furqan is a title only for God’s scriptures and not for the unauthorized collection of Hadith attributed to the prophet. Therefore all the laws we are to uphold must come from the law book itself, which is the Quran.

[6:114] Shall I seek other than GOD as a source of law, when He has revealed to you this book fully detailed? Those who received the scripture recognize that it has been revealed from your Lord, truthfully. You shall not harbor any doubt. [6:115] The word of your Lord is complete,* in truth and justice. Nothing shall abrogate His words. He is the Hearer, the Omniscient.

أَفَغَيْرَ اللَّهِ أَبْتَغِي حَكَمًا وَهُوَ الَّذِي أَنْزَلَ إِلَيْكُمُ الْكِتَابَ مُفَصَّلًا وَالَّذِينَ آتَيْنَاهُمُ الْكِتَابَ يَعْلَمُونَ أَنَّهُ مُنَزَّلٌ مِنْ رَبِّكَ بِالْحَقِّ فَلَا تَكُونَنَّ مِنَ الْمُمْتَرِينَ وَتَمَّتْ كَلِمَتُ رَبِّكَ صِدْقًا وَعَدْلًا لَا مُبَدِّلَ لِكَلِمَاتِهِ وَهُوَ السَّمِيعُ الْعَلِيمُ