Exodus 27:20-21
The Lampstand Oil
20 “You are to command the Israelites to bring you pure oil from crushed olives for the light, in order to keep the lamp burning continually.
21 In the tent of meeting outside the veil that is in front of the testimony,(A) Aaron and his sons are to tend the lamp(B) from evening until morning before the Lord. This is to be a permanent statute(C) for the Israelites throughout their generations.