The Book of Pilgrimage
وَحَدَّثَنِي مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا عَزْرَةُ بْنُ ثَابِتٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، قَالَ حَجَجْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم فَنَحَرْنَا الْبَعِيرَ عَنْ سَبْعَةٍ وَالْبَقَرَةَ عَنْ سَبْعَةٍ .Jabir b. 'Abdullah (Allah be pleased with him) reported:We performed Hajj along with Allah's Messenger (ﷺ), and we sacrificed a camel on behalf of seven persons, and a cow on behalf of seven persons
From Sahih Muslim, whose reports the scholars accept as authentic.