Leviticus 24:1-4

The LORD said to Moses, “Command the people of Israel to bring you pure oil from crushed olives. That oil is for the lamps so that these lamps may never go out. Aaron will keep the lamps burning in the Meeting Tent from evening until morning before the LORD; this is in front of the curtain of the Ark of the Agreement. This law will continue from now on. Aaron must always keep the lamps burning on the lampstands of pure gold before the LORD.