Ikrimah (may Allah have mercy on him) narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both): "We were with the Prophet (peace and blessings be upon him) on a journey, and the day of sacrifice came, so ten men shared in the sacrifice of a camel, and seven in the sacrifice of a cow."
(b) It has been narrated thus with this chain, but the hadith of Abu al-Zubayr from Sayyiduna Jabir (may Allah be pleased with him) is more authentic than it; he was present at Hudaybiyah and was present at Hajj and Umrah, and he informed us that "the Prophet (peace and blessings be upon him) ordered them to have seven men share in a camel," so it is more worthy of acceptance.
(c) It has been narrated from Sufyan al-Thawri from Abu al-Zubayr from Sayyiduna Jabir (may Allah be pleased with him): "We slaughtered seventy camels on the day of Hudaybiyah, a camel on behalf of ten," but I consider it nothing but an error, for al-Firyabi narrated it from al-Thawri and said: a camel on behalf of seven. Likewise Malik bin Anas, Ibn Jurayj, Zuhayr bin Mu'awiyah and others narrated it from Abu al-Zubayr from Jabir, saying: a camel on behalf of seven; Ata bin Abi Rabah also said the same from Jabir, and Muslim bin al-Hajjaj preferred their narration by recording it rather than the narration of others.
(d) As for the hadith of al-Zuhri from Urwah, Muhammad bin Ishaq bin Yasar is alone in mentioning in it a camel on behalf of ten, and the hadith of Ikrimah is narrated only by al-Husayn bin Waqid from Ilba' bin Ahmar. The hadith of Sayyiduna Jabir (may Allah be pleased with him) is more authentic than all of these; he reported their sharing (in sacrificial animals) during Hajj, Umrah and at Hudaybiyah by the command of the Messenger of Allah (peace and blessings be upon him), so it is more worthy of acceptance.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10203