Exodus 39:35

the ark of the testimony with its poles, the mercy seat,

Exodus 25:17

You shall make a mercy seat of pure gold. Two and a half cubits shall be its length, and a cubit and a half its breadth.

Hebrews 9:5

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

Hebrews 9:8

The Holy Spirit is indicating this, that the way into the Holy Place was not yet revealed while the first tabernacle was still standing;

Treasury of Scripture Knowledge

Summary

The ark of the testimony, and the staves thereof, and the mercy seat,

The mercy seat

Bible References

The mercy seat

Exodus 25:17
You shall make a mercy seat of pure gold. Two and a half cubits shall be its length, and a cubit and a half its breadth.
Hebrews 9:5
and above it cherubim of glory overshadowing the mercy seat, of which things we cannot speak now in detail.