Leviticus 1:1-3

The LORD spoke to Moses from the sacred tent and gave him instructions for the community of Israel to follow when they offered sacrifices. Sacrifices to please me must be completely burned on the bronze altar. Bulls or rams or goats are the animals to be used for these sacrifices. If the animal is a bull, it must not have anything wrong with it. Lead it to the entrance of the sacred tent, and I will let you know if it is acceptable to me.