Leviticus 6:9-13

⁹Command Aaron and his sons, saying, This is the law of the burnt offering: the burnt offering shall be on the hearth on the altar all night to the morning; and the fire of the altar shall be kept burning thereon. ¹⁰The priest shall put on his linen garment, and his linen breeches shall he put on his flesh; and he shall take up the ashes whereto the fire has consumed the burnt offering on the altar, and he shall put them beside the altar. ¹¹He shall put off his garments, and put on other garments, and carry forth the ashes outside of the camp to a clean place. ¹²The fire on the altar shall be kept burning thereon, it shall not go out; and the priest shall burn wood on it every morning: and he shall lay the burnt offering in order on it, and shall burn thereon the fat of the peace-offerings. ¹³Fire shall be kept burning on the altar continually; it shall not go out.