Let him first cast a stone...

Every Christian knows the story in St John's Gospel of the adulterous woman who was condemned to be stoned to death. Jesus defends her saying: "He that is without sin among you, let him first cast a stone at her...". This story does not appear anywhere in the Codex Sinaiticus. Nor does it appear in the Codex Vaticanus. According to Bentley, in other manuscripts scribes question the story's authenticity. Evidently it was added to St John's Gospel later.