Leviticus 6:9

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.

Leviticus 6:12

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.

Leviticus 10:6

10:6 Then Moses said to Aaron and to Eleazar and Ithamar his other two sons, “Do not dishevel the hair of your heads and do not tear your garments, so that you do not die and so that wrath does not come on the whole congregation. Your brothers, all the house of Israel, are to mourn the burning which the Lord has caused,