The mercy — seat was the covering of the ark, made exactly to fit the dimensions of it. This propitiatory covering, as it might well be translated, was a type of Christ the great propitiation, whose satisfaction covers our transgressions, and comes between us and the curse we deserve.
Related Commentaries of Exodus 25:17
Exodus 25:17
17 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.