1 Kings 6:13-17

And I will dwell among the children of Israel, and will not forsake my people Israel.

So Solomon built the house, and finished it.

And he built the walls of the house within with boards of cedar, both the floor of the house, and the walls of the cieling: and he covered them on the inside with wood, and covered the floor of the house with planks of fir.

And he built twenty cubits on the sides of the house, both the floor and the walls with boards of cedar: he even built them for it within, even for the oracle, even for the most holy place.

And the house, that is, the temple before it, was forty cubits long.