Leviticus 7:1

In the place where they kill the burnt offering, he shall kill the trespass offering; and its blood he shall sprinkle around on the altar.

He shall offer all of its fat: the fat tail, and the fat that covers the innards,

and he shall take away the two kidneys, and the fat that is on them, which is by the loins, and the cover on the liver, with the kidneys;