Leviticus 6:25

6:25 “Tell Aaron and his sons, ‘This is the law of the sin offering. In the place where the burnt offering is slaughtered the sin offering must be slaughtered before the Lord. It is most holy.

Leviticus 7:2

7:2 In the place where they slaughter the burnt offering they must slaughter the guilt offering, and the officiating priest must splash the blood against the altar’s sides.