Musannaf Ibn Abi Shayba 36:448

Abu Ishaq al-Azdi narrated to us, he said: Abu Uways narrated to me, from Ubayd Allah ibn Umar, from Nafi, from Ibn Umar, who said: I was at Mu'tah, and when we lost Ja'far ibn Abi Talib, we searched for him among the slain. We found in him more than ninety [wounds] between stabs and shots [from arrows]. And we found them on the front part of his body.