G2435–ἱλαστήριος–hilastērios

whom God set forth to be an atoning sacrifice, through faith in his blood, for a demonstration of his righteousness through the passing over of prior sins, in God's forbearance;

ἱλαστήριον hilastērion “a propitiation”

and above it cherubim of glory overshadowing the mercy seat, of which things we can't now speak in detail.

ἱλαστήριον, hilastērion “mercy seat,”