Musnad Ahmad 1756

Al-Mas’oodi told us: An old man who came to us from the Hijaz told us: I saw "Abdullah bin az-Zubair and "Abdullah bin Ja"far in al-Muzdalifah, when Ibn az-Zubair was cutting meat for "Abdullah bin Ja"far. "Abdullah bin Ja’far said: I heard the Messenger of Allah (ﷺ) say: “The best meat is meat from the back."