1 Kings 6:16-20

16He built twenty cubits on the rear of the house with boards of cedar from the floor to the ceiling; he built its interior as the [inner] sanctuary, the Holy of Holies.

17The [rest of the] house, that is, the temple in front of the Holy of Holies, was forty cubits long.

18The cedar on the house within had wood carvings in the shape of gourds and open flowers. Everything was cedar; no stone was visible.

19Then he prepared the Holy of Holies within the house in order to put the ark of the covenant of the Lord there.

20The Holy of Holies was twenty cubits in length, twenty cubits in width, and twenty cubits in height (a cube), and he overlaid it with pure gold. He also overlaid the cedar altar [with gold].