3:86 & 63:1

[3:86] Why should GOD guide people who disbelieved after believing, and after witnessing that the messenger is truth, and after solid proofs have been given to them? GOD does not guide the wicked.

كَيْفَ يَهْدِى ٱللَّهُ قَوْمًا كَفَرُوا۟ بَعْدَ إِيمَـٰنِهِمْ وَشَهِدُوٓا۟ أَنَّ ٱلرَّسُولَ حَقٌّ وَجَآءَهُمُ ٱلْبَيِّنَـٰتُ وَٱللَّهُ لَا يَهْدِى ٱلْقَوْمَ ٱلظَّـٰلِمِينَ

[63:1] When the hypocrites come to you they say, "We bear witness that you are the messenger of GOD." GOD knows that you are His messenger, and GOD bears witness that the hypocrites are liars.

إِذَا جَآءَكَ ٱلْمُنَـٰفِقُونَ قَالُوا۟ نَشْهَدُ إِنَّكَ لَرَسُولُ ٱللَّهِ وَٱللَّهُ يَعْلَمُ إِنَّكَ لَرَسُولُهُۥ وَٱللَّهُ يَشْهَدُ إِنَّ ٱلْمُنَـٰفِقِينَ لَكَـٰذِبُونَ

Some claim that based on the above verses, they can also bear witness to the messenger. However, the fundamental problem with this argument is that, even if such an understanding were granted, the only people who could have made such claims under this paradigm would have been only those who lived during the prophet's time and were in his presence.

Today, it does not make sense for anyone to say they can bear witness to the messenger because he is no longer alive, making it impossible for individuals to make such a claim. After the prophet's death, anyone who did not see him while he was alive could not have borne witness to him. This situation is similar to the prophet Muhammad being informed that he was not a witness to Moses receiving the commandments.

[28:44] You were not present on the slope of the western mount, when we issued the command to Moses; you were not a witness.

وَمَا كُنتَ بِجَانِبِ ٱلْغَرْبِىِّ إِذْ قَضَيْنَآ إِلَىٰ مُوسَى ٱلْأَمْرَ وَمَا كُنتَ مِنَ ٱلشَّـٰهِدِينَ

Since this event happened before his life, he was not among the witnesses. Similarly, today, no one can claim that they bear witness to the prophet because the prophet is dead, and they cannot say they bore witness because they were not alive and with the prophet when he was present on this earth.

Additionally, as stated in the other article, since the prophet is no longer living, even the statement that Muhammad is a messenger of God is false because he is dead, so the correct utterance would be that Muhammad was (kana) a messenger of God.