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

[409] Now when Titus was come into this [upper] city, he admired not only some other places of strength in it, but particularly those strong towers which the tyrants in their mad conduct had relinquished; for when he saw their solid altitude, and the largeness of their several stones, and the exactness of their joints, as also how great was their breadth, and how extensive their length, he expressed himself after the manner following: "We have certainly had God for our assistant in this war, and it was no other than God who ejected the Jews out of these fortifications; for what could the hands of men or any machines do towards overthrowing these towers?" At which time he had many such discourses to his friends; he also let such go free as had been bound by the tyrants, and were left in the prisons. To conclude, when he entirely demolished the rest of the city, and overthrew its walls, he left these towers as a monument of his good fortune, which had proved his auxiliaries, and enabled him to take what could not otherwise have been taken by him.