Exodus 25:17 - Clarke's commentary and critical notes on the Bible

And thou shalt make a mercy seat of pure gold: two cubits and a half shall be the length thereof, and a cubit and a half the breadth thereof. A mercy-seat - כפרת capporeth, from כפר caphar, to cover or overspread; because by an act of pardon sins are represented as being covered, so that they no longer appear in the eye of Divine justice to displease, irritate, and call for punishment; and the person of the offender is covered or protected from the stroke of the broken law. In the Greek version of the Septuagint the word ιλαστηριον, hilasterion, is used, which signifies a propitiatory, and is the name used by the apostle, Hebrews 9:5. This mercy-seat or propitiatory was made of pure gold; it was properly the lid or covering of that vessel so well known by the name of the ark and ark of the covenant. On and before this, the high priest was to sprinkle the blood of the expiatory sacrifices on the great day of atonement: and it was in this place that God promised to meet the people, (see Exodus 25:22); for there he dwelt, and there was the symbol of the Divine presence. At each end of this propitiatory was a cherub, between whom this glory was manifested; hence in Scripture it is so often said that he dwelleth between the cherubim. As the word ιλαστηριον, propitiatory or mercy-seat, is applied to Christ, Romans 3:25, whom God hath set forth to be a Propitiation (ιλαστηριον) through faith in his blood - for the remission of sins that are past; hence we learn that Christ was the true mercy-seat, the thing signified by the capporeth, to the ancient believers. And we learn farther that it was by his blood that an atonement was to be made for the sins of the world. And as God showed himself between the cherubim over this propitiatory or mercy-seat, so it is said, God was in Christ reconciling the world unto himself; 2 Corinthians 5:19, etc. See on Leviticus 7 (note).