I heard Umar bin Khattab say, "Stoning is prescribed in the Book of Allah as a due punishment upon any man or woman who commits adultery after marriage, when the evidence is established, or when there is pregnancy, or a confession."
سمعت عمر بن الخطاب يقول: الرجم في كتاب الله حق على من زنى من الرجال والنساء إذا أحصن، إذا قامت البينة، أو كان الحبل أو الاعتراف.
Malik narrated it in Hudud (8) from Ibn Shihab, from Ubaydullah bin Abdullah bin Utba bin Masud, from Abdullah bin Abbas, and he related it. Bukhari and Muslim narrated it through other routes from Zuhri, both abridged and in full, as mentioned before.