John 8:1-11 records a meeting between Jesus, some scholars, Pharisees, and a woman who has been caught in adultery. The Mosaic law (Leviticus 20:10, and Deuteronomy 22:22) required that she must be executed by stoning. The passage in Deuteronomy is quite definite: "both the man...and the woman must die. You must purge the evil from Israel." They asked Jesus what should be done with the woman. He recommended that the thrower of the first stone be required to be without sin. Since no individual is without sin, his suggestion is equivalent to pardoning the woman. He thus recommended that the woman be allowed to live. This was a quadruple violation of Mosaic Law, which specified the following : Deuteronomy 22:22: Each incidence of adultery was considered an evil blot on the land itself; it had to be purged from Israel. The only method of doing that was to kill the adulterers.
When a person is to be executed under Jewish law, the first stones were to be thrown by the witnesses to the crime. (An trial leading to an execution had to have at least two witnesses. Only then were the remainder of the people allowed to take part in the murder of the criminal.)
There is no passage in the Mosaic law which states that executioners have to be sinless.
There is no passage in the Mosaic law which allows an adulterer to be pardoned.
Later, Jesus said to the woman: "Neither do I condemn thee: go, and sin no more." Through these words, he recognized her adultery as a sin.
This passage is apparently a forgery that was not written by the author(s) of the gospel of John. It was written by an anonymous individual and later inserted after chapter 7 by an anonymous editor. The New International Version of the Bible has a footnote at this point stating: "The earliest and most reliable manuscripts and other ancient witnesses do not have John 7:53 - 8:11." Other manuscripts place it at the end of the Gospel of John. Still others insert it after Luke 21:38. The Jesus Seminar calls it a "floating" or "orphan" story. 1 The Fellows of the Seminar agreed that while "the words did not originate in their present form with Jesus, they nevertheless assigned the words and story to a special category of things they wish Jesus had said and done." The passage is apparently a traditional Christian story that found its way into various later manuscripts but was not part of the original writings by the author(s) of the Gospel of John.