Missing: Mark 9:29

In Mark 9:29, the word "and fasting" is missing in early manuscripts.

RSV:

27 But Jesus took him by the hand and lifted him up, and he arose. 28 And when he had entered the house, his disciples asked him privately, “Why could we not cast it out?” 29 And he said to them, “This kind cannot be driven out by anything but prayer.”

KJV:

27 But Jesus took him by the hand, and lifted him up; and he arose. 28 And when he was come into the house, his disciples asked him privately, Why could not we cast him out? 29 And he said unto them, This kind can come forth by nothing, but by prayer and fasting.