Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[201] Now nine of these gates were on every side covered over with gold and silver, as were the jambs of their doors and their lintels; but there was one gate that was without the [inward court of the] holy house, which was of Corinthian brass, and greatly excelled those that were only covered over with silver and gold. Each gate had two doors, whose height was severally thirty cubits, and their breadth fifteen. However, they had large spaces within of thirty cubits, and had on each side rooms, and those, both in breadth and in length, built like towers, and their height was above forty cubits. Two pillars did also support these rooms, and were in circumference twelve cubits. Now the magnitudes of the other gates were equal one to another; but that over the Corinthian gate, which opened on the east over against the gate of the holy house itself, was much larger; for its height was fifty cubits; and its doors were forty cubits; and it was adorned after a most costly manner, as having much richer and thicker plates of silver and gold upon them than the other. These nine gates had that silver and gold poured upon them by Alexander, the father of Tiberius. Now there were fifteen steps, which led away from the wall of the court of the women to this greater gate; whereas those that led thither from the other gates were five steps shorter.