Musnad Ahmad 33:16

'Abd al-Razzaq and Rawh narrated to us, they said: Malik narrated to us, from Abu al-Zubayr, from Jabir, who said: "We slaughtered at al-Hudaybiyyah with the Messenger of Allah, may Allah bless him and grant him peace, the camel on behalf of seven, and the cow on behalf of seven."