Yahya related to me from Malik from Umara ibn Yasar that Ata ibnYasar told him that Abu Ayyub al-Ansari had told him, "We used tosacrifice one sheep, and a man sacrificed for himself and his family.Then later on people began to compete with each other and it becameboasting."Malik said, "The best that I have heard about asingle camel, cow or sheep, is that a man should sacrifice a camel forhimself and his family. He sacrifices a cow or sheep which he owns forhis family, and shares with them in it. It is disapproved for a groupof people to buy a camel, cow or sheep, to share for the ritual andsacrifices, each man giving a share of its price, and taking a shareof its meat. We have heard the tradition that people do not share inthe ritual. However, it may be that the people of one household canshare."
USC-MSA web (English) reference: Book 23, Hadith 10
Arabic reference: Book 23, Hadith 1040