(Heb. kapporeth, a "covering;" LXX. and N.T., hilasterion; Vulg., propitiatorium), the covering or lid of the ark of the covenant (q.v.). It was of acacia wood, overlaid with gold, or perhaps rather a plate of solid gold, 2 1/2 cubits long and 1 1/2 broad ( Exodus 25:17 ; 30:6 ; 31:7 ). It is compared to the throne of grace ( Hebrews 9:5 ; Ephesians 2:6 ). The holy of holies is called the "place of the mercy-seat" ( 1 Chronicles 28:11 : Leviticus 16:2 ).
It has been conjectured that the censer (thumiaterion, meaning "anything having regard to or employed in the burning of incense") mentioned in Hebrews 9:4 was the "mercy-seat," at which the incense was burned by the high priest on the great day of atonement, and upon or toward which the blood of the goat was sprinkled ( Leviticus 16:11-16 ; Compare Numbers 7:89 and Exodus 25:22 ).