Leviticus 24:3

Without the veil of the testimony, the curtain which hid the Ark of the Covenant with the tables of the testimony from the eyes of all the children of Israel, in the Tabernacle of the Congregation, in the Holy Place, shall Aaron order it from the evening unto the morning before the Lord continually, that is, he was to place the lamps filled with the pure oil on the seven-armed candlestick and light them in the evening, and put them in order in the morning by cleaning them and trimming their wicks. It shall be a statute forever in your generations.