It was narrated from ‘Aishah and Abu Hurairah that when the Messenger of Allah (peace be upon him) wanted to offer a sacrifice, he brought two large, fat, horned, black-and-white, castrated rams. He slaughtered one on behalf of his nation, for whoever testified to Allah with monotheism and that he had conveyed (the Message), and he slaughtered the other on behalf of Muhammad and the family of Muhammad (peace be upon him).
Sunan Ibn Majah, Book 26, Hadith 3241
