The mercy seat was the golden lid over the Ark of the Covenant where God met His people through blood; fulfilled in Christ, our true mercy seat.
The New Testament identifies Jesus Christ as the fulfillment of this type. He is both the true mercy seat and the final sacrifice whose blood covers sin eternally.
See in Scripture: Exodus 25:17–22; Leviticus 16:14–15; Romans 3:25
See also: Propitiation, Atonement