Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 3025
Jabir (Allah be pleased with him) reported: We set out in the state of Ihram for Hajj along, with Allah's Messenger (may peace be upon him). He commanded us that seven perons should join in a camel and a cow for offering sacrifice.