Abu Dawud Book 9, Hadith Number 2782.

Chapter : On the obligation of sacrifice.

Narated By Mikhnaf ibn Sulaym : We were staying with the Apostle of Allah (PBUH) at Arafat; he said: O people, every family must offer a sacrifice and an atirah. Do you know what the atirah is? It is what you call the Rajab sacrifice.

Abu Dawud said: ‘Atriah has been abrogated, and this tradition is an abrogated one.