Albert Barnes Commentary 1 Kings 7:4

"And there were beams in three rows, and window was over against window in three ranks." — 1 Kings 7:4 (ASV)

There were either three rows of windows, one above the other, on each side of the house, or perhaps one row was in each side wall, with the third in a wall running down the middle of the hall along the central row of pillars. The windows were directly opposite one another, providing what is known as a through-light.