And you shall put the mercy seat on the ark of the testimony in the most holy place.
put the mercy seat
Exodus 25:21 And you shall put the mercy seat above on the ark; and in the ark you shall put the testimony that I shall give you.
Exodus 40:20 And he took and put the testimony into the ark, and set the staves on the ark, and put the mercy seat above on the ark:
Hebrews 9:5 And over it the cherubim of glory shadowing the mercy seat; of which we cannot now speak particularly.