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 9:24

9:24 Then fire went out from the presence of the Lord and consumed the burnt offering and the fat parts on the altar, and all the people saw it, so they shouted loudly and fell down with their faces to the ground.