Flay is a strange word to use for preparing a sacrifice to be placed on the altar:

Leviticus 1:5. And he will kill the bull before the LORD*. The priests, Aaron’s sons, will bring the blood and sprinkle the blood all around on the altar that is by the entrance of the Tent of Meeting. 6. And he will flay the burnt offering and cut it into its pieces. 7. And the sons of Aaron the priest will put fire upon the altar and lay the wood in order on the fire, 8. and the priests, Aaron’s sons, will lay the parts, the head and the fat, in order upon the wood that is on the fire which is on the altar.