Exodus 27:21

In the Tabernacle of the Congregation without the veil, which is before the testimony, before the Ark of the Covenant, Aaron and his sons shall order it from evening to morning before the Lord, the lamps burned from the time of the evening sacrifice till the next morning. The Tabernacle is here for the first time called the "tent of meeting," because the Lord met with the representatives of the people when He communicated with them from the mercy-seat. It shall be a statute forever unto their generations on the behalf of the children of Israel. This refers both to the furnishing of the oil on the part of the people and to the lighting of the lamps on the part of the priests. Just as the children of Israel were to be reminded that their light was not to be quenched as long as they remained in the covenant of the Lord, so we Christians should remember that the light of our faith should ever be visible in good works.