Leviticus 1:9

but his inwards and his legs, the intestines, as the lower viscera, and the lower parts of the legs, especially beneath the knees, shall he wash in water, to remove any outward impurities that might be clinging to them; and the priests shall burn all on the altar, to be a burnt sacrifice, an offering made by fire, of a sweet savor unto the Lord. The animal, with its flesh and bones, was burned entire, for the offering signified that the worshiper dedicated himself to the Lord with all his heart and mind, with all the powers of his body and soul, and the rising of the smoke, as the animal was consumed, caused its essence to ascend as a pleasant, acceptable odor to the Lord. In other words, the Lord graciously accepted the worshiper and his service as a member of His Church on earth. God was well pleased with such sacrifices, if they were offered in faith.