16 He partitioned off twenty cubits at the rear of the temple with cedar boards from floor to ceiling to form within the temple an inner sanctuary, the Most Holy Place.

Read 1 Kings 6:16 Using Other Translations

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.
He built twenty cubits of the rear of the house with boards of cedar from the floor to the walls, and he built this within as an inner sanctuary, as the Most Holy Place.
He partitioned off an inner sanctuary—the Most Holy Place—at the far end of the Temple. It was 30 feet deep and was paneled with cedar from floor to ceiling.