Bede's Ecclesiastical History of England, ed. by A.M. Sellar, [1907], at sacred-texts.com
AT this time, the monastery of virgins, called the city of Coludi, above-mentioned, was burned down, through carelessness; and yet all that knew it might have been aware that it happened by reason of the wickedness of those who dwelt in it, and chiefly of those who seemed to be the greatest. But there wanted not a warning of the approaching punishment from the Divine mercy whereby they might have been led to amend their ways, and by fasting and tears and prayers, like the Ninevites, have averted the anger of the just Judge.
For there was in that monastery a man of the Scottish race, called Adamnan,leading a life entirely devoted to God in continence and prayer, insomuch that he never took any food or drink, except only on Sundays and Thursdays; and often spent whole nights in watching and prayer. This strictness in austerity of life he had first adopted from the necessity of correcting the evil that was in him; but in process of time the necessity became a custom.
For in his youth he had been guilty of some sin for which, when he came to himself, he conceived a great horror, and dreaded lest he should be punished for the same by the righteous Judge. Betaking himself, therefore, to a priest, who, he hoped, might show him the way of salvation, he confessed his guilt, and desired to be advised how he might escape the wrath to come. The priest having heard his offence, said, "A great wound requires greater care in the healing thereof; wherefore give yourself as far as you are able to fasting and psalms, and prayer, to the end that thus coming before the presence of the Lord in confession, you may find Him merciful." But he, being oppressed with great grief by reason of his guilty conscience, and desiring to be the sooner loosed from the inward fetters of sin, which lay heavy upon him, answered, "I am still young in years and strong of body, and shall, therefore, easily bear all whatsoever you shall enjoin me to do, if so be that I may be saved in the day of the Lord, even though you should bid me spend the whole night standing in prayer, and pass the whole week in abstinence." The priest replied, "It is much for you to continue for a whole week without bodily sustenance; it is enough to observe a fast for two or three days; do this till I come again to you in a short time, when I will more fully show you what you ought to do, and how long to persevere in your penance." Having so said, and prescribed the measure of his penance, the priest went away, and upon some sudden occasion passed over into Ireland, which was his native country, and returned no more to him, as he had appointed. But the man remembering this injunction and his own promise, gave himself up entirely to tears of penitence, holy vigils and continence; so that he only took food on Thursdays and Sundays, as has been said; and continued fasting all the other days of the week. When he heard that his priest had gone to Ireland, and had died there, he ever after observed this manner of abstinence, which had been appointed for him as we have said; and as he had begun that course through the fear of God, in penitence for his guilt, so he still continued the same unremittingly for the love of God and through delight in its rewards.
Having practised this carefully for a long time, it happened that he had gone on a certain day to a distance from the monastery, accompanied by one the brothers; and as they were returning from this journey, when they drew near to the monastery, and beheld its lofty build-wigs, the man of God burst into tears, and his countenance discovered the trouble of his heart. His companion, perceiving it, asked what was the reason, to which he answered: "The time is at hand when a devouring fire shall reduce to ashes all the buildings which you here behold, both public and private." The other, hearing these words, when they presently came into the monastery, told them to Aebba,the mother of the community. She with good cause being much troubled at that prediction, called the man to her, and straitly questioned him concerning the matter and how he came to know it. He answered, "Being engaged one night lately in watching and singing psalms, on a sudden I saw one standing by me whose countenance I did not know, and I was startled at his presence, but he bade me not to fear, and speaking to me like a friend he said, ‘You do well in that you have chosen rather at this time of rest not to give yourself up to sleep, but to continue in watching and prayer.’ I answered, ‘I know I have great need to continue in wholesome watching and earnest prayer to the Lord to pardon my transgressions.’ He replied, ‘You speak truly, for you and many more have need to redeem their sins by good works, and when they cease from temporal labours, then to labour the more eagerly for desire of eternal blessings; but this very few do; for I, having now gone through all this monastery in order, have looked into the huts and beds of all, and found none of them except yourself busy about the health of his soul; but all of them, both men and women, are either sunk in slothful sleep, or are awake in order to commit sin; for even the cells that were built for prayer or reading, are now converted into places of feasting, drinking, talking, and other delights; the very virgins dedicated to God, laying aside the respect due to their profession, whensoever they are at leisure, apply themselves to weaving fine garments, wherewith to adorn themselves like brides, to the danger of their state, or to gain the friendship of strange men; for which reason, as is meet, a heavy judgement from Heaven with raging fire is ready to fall on this place and those that dwell therein.’" The abbess said, "Why did you not sooner reveal to me what you knew?" He answered, "I was afraid to do it, out of respect to you, lest you should be too much afflicted; yet you may have this comfort, that the blow will not fall in your days." This vision being made known, the inhabitants of that place were for a few days in some little fear, and leaving off their sins, began to do penance; but after the death of the abbess they returned to their former defilement, nay, they committed worse sins; and when they said " Peace and safety," the doom of the aforesaid judgement came suddenly upon them.
That all this fell out after this manner, was told me by my most reverend fellow-priest, Aedgils, who then lived in that monastery. Afterwards, when many of the inhabitants had departed thence, on account of the destruction, he lived a long time in our monastery, and died there. We have thought fit to insert this in our History, to admonish the reader of the works of the Lord, how terrible He is in His doing toward the children of men, lest haply we should at some time or other yield to the snares of the flesh, and dreading too little the judgement of God, fall under His sudden wrath, and either in His righteous anger be brought low with temporal losses, or else be more strictly tried and snatched away to eternal perdition.