The Mudabbar
Malik :: Book 41 : Hadith 41.1.8
Malik related to me from Ibn Shihab from Ubaydullah ibn Abdullah ibn Utba ibn Masud that Abdullah ibn Abbas said, "I heard Umar ibn al-Khattab say, 'Stoning is in the Book of Allah for those who commit adultery, men or women when they are muhsan and when there is clear proof of pregnancy or a confession.' "