Mercy Seat

According to the Bible, the mercy seat (Hebrew: כפורת, Kaporet ; "atonement piece") was an object which rested upon the Ark of the Covenant, and was connected with the rituals of Yom Kippur; the term also appears in the Pauline Epistles, and has a significance in Christian theology. The phrase mercy seat is not a translation of the Hebrew term kapporeth, which appears in its place in the Masoretic text, nor of the Greek term hilasterion, which takes the same place in the Septuagint, but instead is the translation by William Tyndale of the German term Gnadenstuhl, from the same narrative position in the Luther Bible; Gnadenstuhl literally means seat of grace, in the sense of location of grace.

Though kapporeth is probably derived from kaphar, which is often considered to mean cover, the literal meaning of kaphar is wipe out, implying that kapporeth means thing of wiping out/thing of cleansing; the cognate Arabic term kaffarat (also generally taken to mean cover, but from which the word kafir also derives) is used in modern legal contexts to refer to any mechanism of rectifying illegality (ranging from rectifying the failure to fast during Ramadan to the rectification of murder), for example the freeing of slaves after the slave has suffered shocking circumstances could be considered as a kaffarat. Similarly hilasterion etymologically means thing for propitiation, with Hesychius writing that a synonym of hilasterion was thing for catharsis, while the Vulgate translates it as propitiatorium. Thus it is unclear whether the kapporeth was the lid of the Ark, or merely sat on top of the Ark, possibly with the Ark having a cover beneath it.