Leviticus 7:11

And this is the law of the sacrifice of peace offerings, which he shall offer unto the LORD.

This is the law governing the peace offerings offered to the Lord. The peace offerings were especially an expression of thanksgiving and gratitude to God, including thank offerings and freewill offerings, by which people returned to God a portion of what He had provided and acknowledged His claims. Those sacrifices pointed forward to the death of Christ and were designed to preserve faith in the coming Redeemer in the hearts of the people. Because of that purpose, strict heed to the Lord's directions concerning them was of the greatest importance.

In the peace offering the fat alone was burned upon the altar, a certain specified portion was reserved for the priests, and the greater part was returned to the offerer to be eaten by him with family and friends in a sacrificial feast. The service included prayer asking God to accept the offering and bless it for the worshipers' spiritual good, with the people's portion blessed before it was shared in a sacred feast that was solemn yet joyful. In keeping with this sharing, Elkanah gave each family member a share of the offering and gave Hannah a double portion as a sign of regard. The shared meal was meant to direct all hearts in gratitude and faith to the great Sacrifice that was to take away the sin of the world. Properly observed, the service fostered devotion, piety, kindness, and sympathy rather than becoming empty ceremony or self-gratification.