The Book of Pilgrimage
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا مَالِكٌ، ح وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، - وَاللَّفْظُ لَهُ - قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ أَبِي الزُّبَيْرِ عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ قَالَ نَحَرْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم عَامَ الْحُدَيْبِيَةِ الْبَدَنَةَ عَنْ سَبْعَةٍ وَالْبَقَرَةَ عَنْ سَبْعَةٍ .Jabir b. 'Abdullah (Allah be pleased with him) reported:In the year of Hudaibiya (6 H ), we, along with Allah's Messenger (way peace be upon him), sacrificed a camel for seven persons and a cow for seven persons
From Sahih Muslim, whose reports the scholars accept as authentic.