The Hebrew term "kapporet" (Greek: "hilastērion") has been translated as "mercy seat;" however, a more accurate translation would be "means of propitiation" or "place of propitiation".

The "place of propitiation" was the lid of the Ark of the Covenant, a slab of pure gold (approximately 45 inches wide x 27 inches long). This was the throne of God where God sat when He communicated with Moses.

When the high priest enters the Holy of Holies, once a year on the Day of Atonement, to make atonement for sin (Leviticus 16:1-34), he sacrifices a young bull to atone for himself and his family and one unblemished male goat for the nation of Israel.

The blood of the sacrificed bull and goat was sprinkled on the place of propitiation. This represented both the covering of sin (expiation) and the mercy of God to forgive sin (propitiation). This may be why the translation for "kapporet" ultimately became "mercy seat".

Jesus' sacrifice was symbolically seen to have elements of the Day of Atonement in the process of restoring a relationship with God.

Just like the blood of the sacrificed unblemished goat was sprinkled on the Mercy Seat, Jesus provided the blood for the place of propitiation (Rom 3:25; Heb 9:12-14).

Just like the Mercy Seat received the blood to appease God, Jesus was the place of propitiation (1 John 2:2; 1 John 4:10)

Just like the High Priest who alone enters the Holy of Holies and the presence of God with the blood of the goat he sacrificed, Jesus became the High Priest and mediator of the New Covenant (Heb 9:15, 24-26)

The sacrifice of Jesus Christ was more than simply an "expiation", and it was more than simply a "propitiation". When Jesus speaks of fulfilling the Law in Matthew 5:17, He meant it in a literal sense.

Jesus is the High Priest who provides His own blood for the expiation of sins of human beings.

Jesus is the High Priest who provides the place of propitiation for human beings and satisfied the judgment of God.

The Mosaic legislation clearly was concerned about both sin and justice and in Jesus Christ the Mosaic Law was truly fulfilled.