Melachim Alef 6:6-8

Orthodox Jewish Bible

⁶ The lowest story was five cubits broad, and the middle was six cubits broad, and the third was seven cubits broad; for without in the wall of the Beis [Hamikdash] he made narrow ledges round about, that the beams should not be fastened in the walls of the Beis [Hamikdash].

⁷ And the Beis [Hamikdash], when it was under construction, was built of stone made ready before it was brought there; so was neither hammer nor chisel nor any tool of iron heard in the Beis [Hamikdash], while it was under construction.

⁸ The door for the middle story was in the right side of the Beis [Hamikdash]; and they went up with winding stairs into the middle chamber, and out of the middle into the third.