Leviticus 6:10

6:10 Then the priest must put on his linen robe and must put linen leggings over his bare flesh, and he must take up the fatty ashes of the burnt offering that the fire consumed on the altar, and he must place them beside the altar.

Leviticus 10:12

Perpetual Statutes Moses spoke to Aaron

10:12 Then Moses spoke to Aaron and to Eleazar and Ithamar, his remaining sons, “Take the grain offering which remains from the gifts of the Lord and eat it unleavened beside the altar, for it is most holy.