Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
IN this monastery, at that time, certain special manifestations of the heavenly grace are said to have been shown forth; in as much as the tyranny of the Devil had been recently cast out and Christ had begun to reign there. Of these I have thought it proper to perpetuate the memory of one which the most reverend Bishop Acca was wont often to relate to me, affirming that it had been told him by most creditable brothers of the same monastery. About the same time that this province had received the faith of Christ, a grievous pestilence fell upon many provinces of Britain; which, also, by the Divine dispensation, reached to the aforesaid monastery, then governed by the most religious priest of Christ, Eappa;and many, as well of those that had come thither with the bishop, as of those of the same province of the South Saxons who had been lately called to the faith, were snatched away out of this world. The brethren, therefore, thought fit to keep a fast of three days, and humbly to implore the Divine goodness to vouchsafe to have mercy on them, either by delivering from instant death those that were in danger by reason of the disease, or by saving those who were hurried out of this life from the eternal damnation of their souls.
There was at that time in the monastery, a little boy, of the Saxon nation, lately called to the faith ,who had been attacked by the same infirmity, and had long kept his bed. On the second day of the aforesaid fasting and prayer, it happened about the second hour of the day, that this boy was left alone in the place where he lay sick, when on a sudden, through the Divine disposition, the most blessed chiefs of the Apostles vouchsafed to appear to him; for he was a boy of a very simple and gentle disposition, and with sincere devotion observed the mysteries of the faith which he had received. The Apostles therefore, greeting him with loving words, said, "My son, fear not death, concerning which thou art troubled; for this day we will bring thee to the kingdom of Heaven; but first thou must needs wait till the Masses are celebrated, that having received thy voyage provision, the Body and Blood of our Lord, and so being set free from sickness and death, thou mayest be taken up to the everlasting joys in Heaven.
"Call therefore to thee the priest, Eappa, and tell him, that the Lord has heard your prayers, and has favourably looked upon your devotion and your fast, and not one more shall die of this plague, either in the monastery or the lands adjacent to it; but all your people who any where labour under this sickness, shall be raised up from their weakness, and restored to their former health, saving, thee alone, who art this day to be delivered from death, and to be carried into Heaven, to behold our Lord Christ, whom thou hast faithfully served. This favour the Divine mercy has vouchsafed to grant you, through the intercession of the godly King Oswald, beloved of God, who formerly nobly ruled over the nation of the Northumbrians, with the authority of a temporal kingdom and the devotion of Christian piety which leads to the eternal kingdom. For this very day that king was killed in body by the infidels in war, and straightway taken up to Heaven to the everlasting joys of souls, and brought into fellowship with the number of the elect. Let them look in their records,wherein the burial of the dead is set down, and they will find that he was, this day, as we have said, taken out of this world. Let them, therefore, celebrate Masses in all the oratories of this monastery, either in thanksgiving because their prayers are heard, or else in memory of the aforesaid King Oswald, who once governed their nation, and therefore humbly prayed to the Lord for them, as for converts of his nation; and let all the brethren assemble in the church, and all communicate in the heavenly Sacrifices, and so let them cease to fast, and refresh the body also with the food that belongs to it."
The boy called the priest, and repeated all these words to him; and the priest carefully inquired after the habit and form of the men that had appeared to him. He answered, "Their habit was altogether noble, and their countenances most pleasant and beautiful, such as I had never seen before, nor did I think there could be any men so fair and comely. One of them indeed was shorn like a clerk, the other had a long beard; and they said that one of them was called Peter, the other Paul; and they were the servants of our Lord and Saviour Jesus Christ, sent by Him from Heaven to protect our monastery." The priest believed what the boy said, and going thence immediately, looked in his chronicle, and found that King Oswald had been killed on that very day. He then called the brethren, ordered dinner to be provided, Masses to be said, and all of them to communicate as usual; causing also a part of the same Sacrifice of the Lord’s Oblation to be carried to the sick boy.
Soon after this, the boy died, on that same day; and by his death proved that the words which he had heard from the Apostles of Christ were true. And this moreover bore witness to the truth of his words, that none besides himself, belonging to the same monastery, was taken away at that time. And without doubt, by this vision, many that heard of it were wonderfully excited to implore the Divine mercy in adversity, and to submit to the wholesome remedy of fasting. From that time, the day of commemoration of that king and soldier of Christ began to be yearly honoured with the celebration of Masses, not only in that monastery, but in many other places.