Then each went to his own home, but Jesus went to the Mount of Olives. At dawn he appeared again in the temple courts, where all the people gathered around him, and he sat down to teach them. The teachers of the law and the Pharisees brought in a woman caught in adultery. They made her stand before the group and said to Jesus, “Teacher, this woman was caught in the act of adultery. In the Law Moses commanded us to stone such women. Now what do you say?” They were using this question as a trap, in order to have a basis for accusing him. But Jesus bent down and started to write on the ground with his finger. When they kept on questioning him, he straightened up and said to them, “Let any one of you who is without sin be the first to throw a stone at her.” Again he stooped down and wrote on the ground. At this, those who heard began to go away one at a time, the older ones first, until only Jesus was left, with the woman still standing there. Jesus straightened up and asked her, “Woman, where are they? Has no one condemned you?” “No one, sir,” she said. “Then neither do I condemn you,” Jesus declared. “Go now and leave your life of sin.”
In my Bible it also says: The earliest manuscripts and many other ancient witnesses do not have John 7:53—8:11. A few manuscripts include these verses, wholly or in part, after John 7:36, John 21:25, Luke 21:38 or Luke 24:53.
DA Carson agrees that this is almost certainly a later interpolation from non-Johannine sources. He does, however, believe that such an incident did take place and deals with it in his commentary.
I am struck that this is the sort of story that Christians would rather leave out than put in, and therefore I shall be commenting on it in the next few days.