Exodus 29:22, 24, 26

“Also you shall take the fat of the ram, the fat tail, the fat that covers the entrails, the fatty lobe attached to the liver, the two kidneys and the fat on them, the right thigh (for it is a ram of consecration)

and you shall put all these in the hands of Aaron and in the hands of his sons, and you shall wave them as a wave offering before the LORD.

“Then you shall take the breast of the ram of Aaron’s consecration and wave it as a wave offering before the LORD; and it shall be your portion.