Res Gestae

And while the Romans now pressed hard on those who gave way, and now met those who ventured to charge, the men who carried the fire-pans, stooping low and creeping along, pushed live coals into the joints of one of the mounds, which was built of the boughs of various kinds of trees, of rushes, and of bundles of cane. These, as soon as the dry fuel caught fire, at once

But when the coming of evening put an end to the fighting, and both sides withdrew for a brief rest, the emperor, divided between various plans and pondering them—since pressing reasons urged a longer attempt to destroy Phaenicha, a fortress opposed as an almost unsurmountable barrier to the enemy’s inroads; but the lateness of the season dissuaded him—finally decided to stay there, and to carry on light skirmishes, thinking that perhaps the Persians would yield through lack of supplies. But the result was not what he looked for.