Exodus 27:20-21

Young's Literal Translation

²⁰ `And thou -- thou dost command the sons of Israel, and they bring unto thee pure beaten olive oil for the light, to cause the lamp to go up continually;

²¹ in the tent of meeting, at the outside of the vail, which [is] over the testimony, doth Aaron -- his sons also -- arrange it from evening till morning before Jehovah -- a statute age-during to their generations, from the sons of Israel.