Exodus 27:20-21

BRG Bible

²⁰ ¶ And thou shalt command the children of Israel, that they bring thee pure oil olive beaten for the light, to cause the lamp to burn always.

²¹ In the tabernacle of the congregation without the vail, which is before the testimony, Aaron and his sons shall order it from evening to morning before the Lord: it shall be a statute for ever unto their generations on the behalf of the children of Israel.