Exodus 26:34

And you will put the atonement cover on the ark of the testimony in the {most holy place}.

Exodus 25:21

And you will put the atonement cover above onto the ark, and into the ark you will put the testimony that I will give you.

Exodus 40:20

And he took and he put the testimony into the ark, and he placed the poles on the ark, and he put the atonement cover on the ark, above [it].

Hebrews 9:5

And above it [were] the cherubim of glory overshadowing the mercy seat, about which it is not now [possible] to speak in detail.

Treasury of Scripture Knowledge

Summary

And thou shalt put the mercy seat upon the ark of the testimony in the most holy place.

General references

Bible References

Put the mercy seat

Exodus 25:21
And you will put the atonement cover above onto the ark, and into the ark you will put the testimony that I will give you.
Exodus 40:20
And he took and he put the testimony into the ark, and he placed the poles on the ark, and he put the atonement cover on the ark, above [it].
Hebrews 9:5
And above it [were] the cherubim of glory overshadowing the mercy seat, about which it is not now [possible] to speak in detail.

General references

Exodus 40:3
And you will put there the ark of the testimony, and you will cover over the ark [with] the curtain.
Mark 15:38
And the curtain of the temple was torn in two from top to bottom.