Joseph Benson's Commentary of the Old and New Testaments - Leviticus 6:9
Leviticus 6:9. Command Aaron and his sons Having instructed the people concerning the sacrifices to be brought by them, Moses now proceeds, at God’s command, to direct the priests respecting several parts of their official services. This is the law of the burnt-offering Of the daily one, as the following words show, which may be better rendered, This burnt- offering shall be on the burning (the fire) upon the altar all night until the morning, and the fire of the altar shall be... read more
Albert Barnes' Notes on the Whole Bible - Leviticus 6:13
The fire shall ever be burning - This was a symbol of the never-ceasing worship which Yahweh required of His people. It was essentially connected with their acts of sacrifice. read more