Hophni and Phinehas wanted their portion before the Lord received his.1 In terms of order, the fat was supposed to be burned before any food was consumed (cf. Leviticus 3:1–11). The fat portions would be the fat around the organs but not the fat that is mixed in with the muscle. These portions were understood to be the richest part of the animal which is why they were exclusively reserved for the Lord (cf. Genesis 4:4; Leviticus 3:17; Leviticus 7:23–25).2
15 Moreover, before the fat was burned, the priest’s servant would come and say to the man who was sacrificing, “Give meat for the priest to roast, for he will not accept boiled meat from you but only raw.”