Yahya related to me from Malik from Nafi that Abdullah ibn Umar said, "Someone who vows to sacrifice a camel or a cow to Allah should garland it with two sandals about its neck, and brand it by causing blood to flow from its side. He should then sacrifice it either at the House or at Mina on the day of sacrifice. There are no other correct places apart from those. However, someone who vows to slaughter a camel or a cow simply as a sacrifice can sacrifice it wherever he wishes."