Leviticus 24:3

“And you shall command the sons of Israel, that they bring you clear oil of beaten olives for the light, to make a lamp burn continually.

‘It is a perpetual statute throughout your generations in all your places of habitation: you shall not eat any fat or any blood.’”

“And the assignment of Eleazar the son of Aaron the priest is the oil for the light and the fragrant incense and the continual grain offering and the anointing oil—the assignment of all the tabernacle and of all that is in it, with the sanctuary and its furnishings.”

“So you shall keep the responsibility of the sanctuary and the responsibility of the altar, so that there will no longer be wrath on the sons of Israel.

and the lamp of God had not yet gone out, and Samuel was lying down in the temple of Yahweh where the ark of God was,