Allah's Messenger. I have committed adultery. He (the Holy Prophet) turned away from him, He (again) came round facing him and said to him: Allah's Messenger, I have committed adultery. He (the Holy Prophet) turned away until he did that four times, and as he testified four times against his own self, Allah's Messenger (ﷺ) called him and said: Are you mad? He said: No. He (again) said: Are you married? He said: Yes. Thereupon Allah's Messenger (ﷺ) said: Take him and stone him.
Sahih Muslim Book 29, Hadith 23