1 Samuel 2:13-14

13Now this was the custom of the kohanim with the people: whenever any man offered a sacrifice, the kohen’s servant would come along, while the meat was boiling, with a three-pronged fork in his hand,

14and he would thrust it into the pan, or kettle, or caldron or pot. Whatever the fork brought up, the kohen would take for himself. This is how they dealt with all the Israelites who came there to Shiloh.