Maliks Muwatta Book 041, Hadith Number 007.

Section : Stoning.

Malik related to me from Suhayl ibn Abi Salih from his father from Abu Hurayra that Sad ibn Ubada said to the Messenger of Allah, may Allah bless him and grant him peace, "What do you think I should do if I were to find a man with my wife? Should I leave him there until I had brought four witnesses?" The Messenger of Allah, may Allah bless him and grant him peace, said, "Yes."