In the Tent of Meeting, outside the veil that is in front of the Testimony, Aaron and his sons are to tend the lamps before the LORD from evening until morning. This is to be a permanent statute for the Israelites for the generations to come.
We read of the candlestick in the twenty-fifth chapter; here is an order given for the keeping of the lamps constantly burning in it, else it was useless; in every candlestick there should be a burning and shining light; candlesticks without candles are as wells without water or as clouds without rain. Now, 1. The people were to provide the oil; from them the Lord's ministers must have their maintenance.
Commenting on Exodus 27:20-21
In the tabernacle of the congregation,.... The reasons usually given for this name of the tabernacle are, either because the children of Israel gathered and met together here at certain times, or because here the Lord met with Moses, and his successors, as he had promised, Exo 25:22, but neither of them will hold good; not the first, because the place where the candlestick was...
shall order it from evening to morning--The tabernacle having no windows, the lamps required to be lighted during the day. JOSEPHUS says that in his time only three were lighted; but his were degenerate times, and there is no Scripture authority for this limitation.