Abu Dawood: Hadith 4521

On his father's authority, said that his grandfather told that a A man came to the Prophet (ﷺ) crying for help. He said: His slave-girl, Messenger of Allah! He said: Woe to you, what happened with you ? He said that it was an evil one. He saw the slave-girl of his master; he became jealous of him, and cut off his penis. The Messenger of Allah (ﷺ) said: Bring the man to me. The man was called, but people could not get control over him. The Messenger of Allah (ﷺ) then said: Go away, you are free. He asked: Messenger of Allah! upon whom does my help lie? He replied: On every believer, or he said: On every Muslim.

Abu Dawud said: The name of the man who was emancipated was Rawh b. Dinar

Abu Dawud said: The man who cut off the penis was Zinba'

Abu Dawud said: The Zinba' Abu Rawh was master of the slave.