Amr heard Ibn Abi Awfa (may Allah be pleased with him), the Companion of the Messenger of Allah (peace and blessings be upon him), who had been present at the Pledge of Ridwan, say: We were 1300 that day, and (the tribe of) Aslam that day were one-eighth of the Muhajirun.
(b) This Amr is Ibn Murrah, and the more likely (to be correct) is the narration of Amr bin Dinar from Jabir. Likewise Ma'qil bin Yasar, Salamah bin al-Akwa' and al-Bara' bin Azib (may Allah be pleased with them) narrated it, and all of them were present at Hudaybiyah, except that in one narration from al-Bara' (it says) that they were 1400 or more on the day of Hudaybiyah; it is as though they were in doubt about the excess, or (the doubt came from) some of the narrators from al-Bara'. And Jabir bin Abdullah (may Allah be pleased with them both) made clear, in the narration of Abu al-Zubayr from him, that they slaughtered a camel on behalf of seven and a cow on behalf of seven; so it is as though they slaughtered the seventy (camels) on behalf of some of them and slaughtered cows on behalf of the rest, one for every seven.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10202