MERCY SEAT. Specifically this refers to the lid or gold plate measuring about 2 1/2 by 1 1/2 cubits covering the Ark of the covenant. Resting on top of this plate were two cherubim placed antithetically with outspread wings (Exod 25:17, 22).

The Heb. name for this solid gold slab is kapporeth, which is best rendered in Eng. as “propitiatory.” The paraphrase “mercy seat” by Tyndale was adopted from Luther’s rendering “Gnadensthul.” Martin Noth suggests that Luther did this on the basis of the Gr. and Lat. trs. of the Heb. (cf. also Heb 9:5). (Martin Noth, Das Zweite Buch Moses in das Alte Testament Deutsch, Göttingen, pp. 164-167, or Exodus, London: SCM Press [1962], at reference.) Even though the literal meaning of the Heb. word may mean “lid,” it is quite apparent from the levitical ritual on the Day of Atonement that its meaning was “propitiate.” (Cf. also the LXX and NT hilasterion.)

The mercy seat seems to be the nearest approximation of the presence of God among the Israelites. They were not permitted to make a material representation of God. The pillar of cloud by day and the pillar of fire by night, which represented God’s presence among them, hovered over the mercy seat where the high priest sprinkled the blood for the congregation of Israel on the Day of Atonement. Apparently it was not the lid or the cherubim, but the space between the cherubim that represented God’s presence among them. This space could not be confined nor controlled by man. In this manner the mercy seat conveyed to the Israelites the idea that God was in their midst without a material representation.

International Standard Bible Encyclopedia (1915)

The name for the lid or covering of the ark of the covenant (Ex 25:17, etc.). The Old Testament term means "covering," then, like the New Testament word, "propitiatory" (compare kipper, "to cover guilt," "to make atonement"). The ark contained the two tables of stone which witnessed against the sin of the people. The blood of sacrifice, sprinkled on the mercy-seat on the great day of atonement, intercepted, as it were, this condemning testimony, and effected reconciliation between God and His people. See Atonement; Day of Atonement; PROPITIATION; ARK OF THE COVENANT. In Ro 3:25, Jesus is said to be set forth as "a propitiation (literally, "propitiatory"), through faith, in his blood," thus fulfilling the idea of the mercy-seat (compare Heb 9:5,7,11,12, etc.).

W. Shaw Caldecott