Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates this statement of the Noble Prophet (peace and blessings be upon him): "Whoever sends an animal for sacrifice as a voluntary act, and then that animal (is lost or dies), then if he wishes, he may give another animal in its place, and if he wishes, he may eat it. But if the animal was for a vow, then he must give another animal in its place."