Leviticus 6:8-10

And the LORD spake unto Moses, saying, Command Aaron and his sons, saying, This {is} the law of the burnt offering: It {is} the burnt offering, because of the burning upon the altar all night unto the morning, and the fire of the altar shall be burning in it. {because...: or, for the burning} And the priest shall put on his linen garment, and his linen breeches shall he put upon his flesh, and take up the ashes which the fire hath consumed with the burnt offering on the altar, and he shall put them beside the altar.