Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
THE same Berthun told another miracle concerning the said bishop. When the most reverend Wilfrid, after a long banishment, was admitted to the bishopric of the church of Hagustald, and the aforesaid John, upon the death of Bosa, a man of great sanctity and humility, was, in his place, appointed bishop of York, he himself came, once upon a time, to the monastery of nuns, at the place called Wetadun, where the Abbess Heriburg then presided. "When we were come thither," said he, "and had been received with great and universal joy, the abbess told us, that one of the nuns, who was her own daughter after the flesh, laboured under a grievous sickness, for she had been lately let blood in the arm, and whilst she was under treatment, was seized with an attack of sudden pain, which speedily increased, while the wounded arm became worse, and so much swollen, that it could scarce be compassed with both hands; and she lay in bed like to die through excess of pain. Wherefore the abbess entreated the bishop that he would vouchsafe to go in and give her his blessing; for she believed that she would soon be better if he blessed her or laid his hands upon her. He asked when the maiden had been let blood, and being told that it was on the fourth day of the moon, said, ‘You did very indiscreetly and unskilfully to let blood on the fourth day of the moon; for I remember that Archbishop Theodore, of blessed memory, said, that blood-letting at that time was very dangerous, when the light of the moon is waxing and the tide of the ocean is rising. And what can I do for the maiden if she is like to die?’
"But the abbess still earnestly entreated for her daughter, whom she dearly loved, and designed to make abbess in her stead, and at last prevailed with him to go in and visit the sick maiden. Wherefore he went in, taking me with him to the maid, who lay, as I said, in sore anguish, and her arm swelling so greatly that it could not be bent at all at the elbow; and he stood and said a prayer over her, and having given his blessing, went out. Afterwards, as we were sitting at table, at the usual hour, some one came in and called me out, saying, ‘Quoenburg’ (that was the maid’s name) ‘desires that you should immediately go back to her.’ This I did, and entering the chamber, I found her of more cheerful countenance, and like one in good health. And while I was sitting beside her, she said, "Shall we call for something to drink? ‘—‘ Yes,’ said I, ‘and right glad am I, if you can.’ When the cup was brought, and we had both drunk, she said, ‘As soon as the bishop had said the prayer for me and given me his blessing and had gone out, I immediately began to mend; and though I have not yet recovered my former strength, yet all the pain is quite gone both from my arm, where it was most burning, and from all my body, as if the bishop had carried it away with him; notwithstanding the swelling of the arm still seems to remain.’ But when we departed thence, the cure of the pain in her limbs was followed by the assuaging of the grievous swelling; and the maiden being thus delivered from pains and death, returned praise to our Lord and Saviour, in company with His other servants who were there.