Charles Ellicott Commentary Exodus 29:22

"Also thou shalt take of the ram the fat, and the fat tail, and the fat that covereth the inwards, and the caul of the liver, and the two kidneys, and the fat that is upon them, and the right thigh (for it is a ram of consecration)," — Exodus 29:22 (ASV)

You shall take from the ram the fat ... — These were the portions commonly burned on the altar in the case of peace offerings. (See Leviticus 3:9-11.) By “the rump” is meant the broad fat tail which characterizes Oriental sheep, and which is said to weigh from six to twenty pounds. (Fellows, Asia Minor, p. 10. Compare to Herodotus iii. 113; Leo Africanus 9 p. 293A.)

The caul above the liver. — See Note 2 on Exodus 29:13.