The Lord spoke to Moses:
References for Leviticus 6:8
"Command Aaron and his sons: This is the law of the burnt offering; the burnt offering itself must remain on the altar's hearth all night until morning, while the fire of the altar is kept burning on it.
References for Leviticus 6:9
The priest is to put on his linen robe and linen undergarments. He is to remove the ashes of the burnt offering the fire has consumed on the altar, and place them beside the altar.
References for Leviticus 6:10
Then he must take off his garments, put on other clothes, and bring the ashes outside the camp to a ceremonially clean place.
The fire on the altar is to be kept burning; it must not go out. Every morning the priest will burn wood on the fire. He is to arrange the burnt offering on the fire and burn the fat portions from the fellowship offerings on it.
Fire must be kept burning on the altar continually; it must not go out.
References for Leviticus 6:13