1 Kings 6:18

He built the walls of the house within with boards of cedar; from the floor of the house to the walls of the ceiling, he covered them on the inside with wood. He covered the floor of the house with cypress boards.

He built twenty cubits of the back part of the house with boards of cedar from the floor to the ceiling. He built this within, for an inner sanctuary, even for the most holy place.

In front of the temple sanctuary was forty cubits long.

He prepared an inner sanctuary in the middle of the house within, to set the ark of the LORD’s covenant there.

Within the inner sanctuary was twenty cubits in length, and twenty cubits in width, and twenty cubits in its height. He overlaid it with pure gold. He covered the altar with cedar.

So Solomon overlaid the house within with pure gold. He drew chains of gold across before the inner sanctuary, and he overlaid it with gold.