Leviticus 6:9-13

6:9 “Command Aaron and his sons, ‘This is the law of the burnt offering. The burnt offering is to remain on the hearth on the altar all night until morning, and the fire of the altar must be kept burning on it. 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. 6:11 Then he must take off his clothes and put on other clothes, and he must bring the fatty ashes outside the camp to a ceremonially clean place, 6:12 but the fire which is on the altar must be kept burning on it. It must not be extinguished. So the priest must kindle wood on it morning by morning, and he must arrange the burnt offering on it and offer the fat of the peace offering up in smoke on it. 6:13 A continual fire must be kept burning on the altar. It must not be extinguished.