Leviticus 7:34
For the wave breast and the heave shoulder have I taken of the children of Israel from off the sacrifices of their peace offerings, and have given them unto Aaron the priest and unto his sons by a statute for ever from among the children of Israel.
The wave breast and the heave, right shoulder taken from the peace offerings of Israel were allotted to Aaron and his sons as their specified priestly share. Only the fat was to be burned on the altar as an offering to God, while the remaining and greater part was to be returned to the offerer to be eaten by him and his friends in a sacrificial feast. The peace offerings were especially an expression of thanksgiving to God, pointing forward to the death of Christ. They were designed to preserve faith in the coming Redeemer in the hearts of the people and to direct all hearts in gratitude and faith to the great Sacrifice that was to take away the sin of the world.
These precise directions were given to keep the priests from taking more than their appointed share, and for that reason they were to be strictly heeded in the most solemn manner. Hophni and Phinehas, the sons of Eli, violated this allotment because they did not realize the solemnity of the symbolic service but used it for self-indulgence. They used the great number of sacrifices at the annual feasts to enrich themselves at the expense of the people. Not content with the part allotted them, they demanded an additional portion beyond their right and seized whatever portion pleased them. They refused to wait even until the fat had been burned as an offering to God, demanding the meat beforehand, depriving the offerers of their portion and dishonoring the sacred offering. When denied they persisted in their claim and threatened to take it by violence.