Leviticus 24:3
Without the vail of the testimony, in the tabernacle of the congregation, shall Aaron order it from the evening unto the morning before the Lord continually: it shall be a statute for ever in your generations.
Cross-references
Exodus 27:21
Parallel
Exodus 27:21 gives the identical instruction for Aaron to tend the lamp from evening to morning, repeating the statute.
Numbers 18:5
Related theme
Numbers 18:5 charges priests to guard the sanctuary, a broader duty encompassing the lamp tending described here.