Res Gestae

Now, while this accumulation of misfortunes was raging, suddenly with peals of thunder rain poured from the black clouds and scattered the hordes roaring around the city; but they returned to the circular rampart formed by their wagons,[*](See xxxi. 7, 5, 7.) and carried their measureless arrogance so far as to send an envoy with a threatening letter, ordering our men to surrender the city on receiving a pledge

The messenger did not dare to enter the city, and the letter was delivered by a certain Christian and read: but it was scorned, as was fitting, and the rest of the day and the whole night were spent in preparing defensive works. For the gates were blocked from within with huge rocks, the unsafe parts of the walls were strengthened, artillery was placed in suitable places for hurling missiles or rocks in all directions, and a supply of water that was sufficient was stored nearby; for on the day before some of those who fought were tormented with thirst almost to the point of death.