Exodus 29:27

‘His own hands are to bring offerings by fire to Yahweh. He shall bring the fat with the breast, that the breast may be waved as a wave offering before Yahweh.

‘And you shall give the right thigh to the priest as a contribution from the sacrifices of your peace offerings.

‘For I have taken the breast of the wave offering and the thigh of the contribution from the sons of Israel from the sacrifices of their peace offerings, and I have given them to Aaron the priest and to his sons as a perpetual statute taken from the sons of Israel.

This is the law of the burnt offering, the grain offering and the sin offering and the guilt offering and the ordination offering and the sacrifice of peace offerings,

But the breasts and the right thigh Aaron waved as a wave offering before Yahweh, just as Moses had commanded.

Then the cook took up the leg with what was on it and set it before Saul. And Samuel said, “Here is what has been reserved! Set it before you and eat, because it has been kept for you until the appointed time, since I said I have invited the people.” So Saul ate with Samuel that day.