Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
ANOTHER notable miracle of the same father is related by many such as were likely to have knowledge thereof; for during the time that he was bishop, the hostile army of the Mercians, under the command of Penda, cruelly ravaged the country of the Northumbrians far and near, even to the royal city,which has its name from Bebba, formerly its queen. Not being able to take it by storm or by siege, he endeavoured to burn it down; and having pulled down all the villages in the neighbourhood of the city, he brought thither an immense quantity of beams, rafters, partitions, wattles and thatch, wherewith he encompassed the place to a great height on the land side, and when he found the wind favourable, he set fire to it and attempted to burn the town.
At that time, the most reverend Bishop Aidan was dwelling in the Isle of Fame,which is about two miles from the city; for thither he was wont often to retire to pray in solitude and silence; and, indeed, this lonely dwelling of his is to this day shown in that island. When he saw the flames of fire and the smoke carried by the wind rising above the city walls, he is said to have lifted up his eyes and hands to heaven, and cried with tears, "Behold, Lord, how great evil is wrought by Penda!" These words were hardly uttered, when the wind immediately veering from the city, drove back the flames upon those who had kindled them, so that some being hurt, and all afraid, they forebore any further attempts against the city, which they perceived to be protected by the hand of God.