The cover of the ark of the covenant, before which the high priest spattered blood of sin offerings on Atonement Day.

Bible translations render the Hebrew term kap·poʹreth variously as “mercy seat” (KJ, RS, Yg), “propitiatory” (AT, Dy), “cover” (Le), “ark-cover” (JP), or “cover,” “propitiatory cover” (NW). The Hebrew term is from a root verb meaning “cover,” “cover over (sin).”

As Jehovah instructed Moses, the craftsman Bezalel made a cover of pure gold for the sacred chest or ark of the covenant, 2.5 cubits (111 cm; 44 in.) long and 1.5 cubits (67 cm; 26 in.) wide. It was surmounted by two golden cherubs, one at each end of the cover, their wings spread upward,  screening the cover. The cherubs’ faces were toward the cover. The Ark was placed in the Most Holy compartment of the tabernacle.​—Ex 25:17-21; 37:1, 6-9.

On the Day of Atonement (yohm hak·kip·pu·rimʹ, meaning “day of the coverings or propitiations” [Le 23:27, 28]), the high priest entered the Most Holy and spattered some of the bull’s blood before the cover (at its front, or east side) and then did the same with the blood of the goat. (Le 16:14, 15) Thus the gold cover of the Ark played a special role in the typical propitiation (covering) of sins.

From between the cherubs on the propitiatory cover, God spoke when he desired to communicate with Moses or with the high priest. (Ex 25:22; Nu 7:89; compare Le 10:8-10; Nu 27:18-21.) Jehovah said that he would appear in a cloud over the cover of the Ark. This cloud apparently glowed or shone, lighting up the Most Holy compartment.​—Le 16:2; compare Ps 80:1.

In 1 Chronicles 28:11 the Most Holy, the innermost compartment of the temple, is referred to as “the house of the kap·poʹreth.” In this instance the Hebrew word is evidently not used simply as designating a lid, or cover, for a chest, but is employed with regard to the special function of the cover in the propitiation of sins. Accordingly, the expression is rendered “the house of the atonement” (Yg), “the house of propitiation” (AT), “the house of the propitiatory cover” (NW).

Symbolic. At Hebrews 9:5 the Greek word hi·la·steʹri·on, “propitiatory,” is used for the cover of the Ark. In the type, or pattern, God’s presence was represented between the two cherubs over the propitiatory cover. (Le 16:2; Ex 25:22) The inspired writer of the book of Hebrews points out that these things were symbolic. As the high priest on the Day of Atonement entered the Most Holy with sacrificial blood, so Christ took the value of his sacrifice, not before a literal propitiatory cover, but before the very presence of Jehovah God in heaven.​—Le 16:15; Heb 9:11-14, 24-28.