Fire shall be kept burning on the altar continually; it shall not go out.
Hitherto we have had the instructions which Moses was directed to give to the people concerning the sacrifices; but here begin the instructions he was to give to the priests; he must command Aaron and his sons, Lev 6:9. The priests were rulers in the house of God, but these rulers must be ruled; and those that had the command of others must themselves be commanded.
Commenting on Leviticus 6:8-13
The fire shall ever be burning upon the altar,.... This was what first fell from heaven, Lev 9:24 and which in after ages was maintained by constant fuel put unto it, there being every day burnt offerings upon it; which was an emblem of the love of Christ to his people, which is ever in a flame and burning, and can never be quenched by...
The fire shall ever be burning - See on Lev 6:9 (note) and Lev 6:20 (note). In imitation of this perpetual fire, the ancient Persian Magi, and their descendants the Parses, kept up a perpetual fire; the latter continue it to the present day. This is strictly enjoined in the Zend Avesta, which is a code of laws as sacred among them as the Pentateuch is among the Jews.