As soon as the darkness fell, he set his men to work.

[16] The mouths of the trenches were opened, and during the night the water poured in, so that the river-bed formed a highway into the heart of the town.
[17] When the great stream had taken to its new channel, Cyrus ordered his Persian officers to bring up their thousands, horse and foot alike, each detachment drawn up two deep, the allies to follow in their old order.

[18] They lined up immediately, and Cyrus made his own bodyguard descend into the dry channel first, to see if the bottom was firm enough for marching.

[19] When they said it was, he called a council of all his generals and spoke as follows: [20] "My friends, the river has stepped aside for us; he offers us a passage by his own high-road into Babylon.

We must take heart and enter fearlessly, remembering that those against whom we are to march this night are the very men we have conquered before, and that too when they had their allies to help them, when they were awake, alert, and sober, armed to the teeth, and in their battle order.