Histories

Seeing that he produced works equal to his words, the Babylonians were overjoyed and ready to serve him in every way. When the agreed number of days was past, he led out once more a chosen body of Babylonians, and slaughtered the two thousand men of Darius' army.

When the Babylonians saw this work too, the praise of Zopyrus was on everyone's lips. The agreed number of days once again passing, he led out his men to the place he had named, where he surrounded the four thousand and slaughtered them. And when he had done this, Zopyrus was the one man for Babylon [44.4,32.55] (deserted settlement), Babil, Iraq, AsiaBabylon: he was made the commander of their armies and guard of the walls.

So when Darius assaulted the whole circuit of the walls, according to the agreed plan, then Zopyrus' treason was fully revealed. For while the townsmen were on the wall defending it against Darius' assault, he opened the gates called Cissian and Belian, and let the Persians inside the walls.