Xenophon, Cyropaedia
Walter Miller, Ed.

And now when evening had come, the relief-corps¹ for the former garrison came from the city, both horse and foot. He thought, therefore, that he had a large army at hand; for the two garrisons were there together and he himself had come with a large force of cavalry and infantry. Accordingly, he decided that it was best to make a foray into the Median territory and he thought that thus the exploit of the hunt would appear more brilliant and that the number of animals captured would be immense. And so, rising early, he led his army out; the infantry he left together at the frontier, while he himself, riding up with the horse to the outposts of the Medes, took his stand there with most of his bravest men about him, to prevent the Median guards from coming to the rescue against those who were scouring the country; and he sent out the proper men in divisions, some in one direction, some in another, to scour the country, with orders to capture whatever they came upon and bring it to him.

So they were engaged in these operations.