Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
THUS wrote the aforesaid Pope Boniface for the salvation of King Edwin and his nation. But a heavenly vision, which the Divine Goodness was pleased once to reveal to this king, when he was in banishment at the court of Redwald, king of the Angles, was of no little use in urging him to receive and understand the doctrines of salvation. For when Paulinus perceived that it was a difficult task to incline the king's proud mind to the humility of the way of salvation and the reception of the mystery of the life-giving Cross, and at the same time was employing the word of exhortation with men, and prayer to the Divine Goodness, for the salvation of Edwin and his subjects; at length, as we may suppose, it was shown him in spirit what the nature of the vision was that had been formerly revealed from Heaven to the king. Then he lost no time, but immediately admonished the king to perform the vow which he had made, when he received the vision, promising to fulfil it, if he should be delivered from the troubles of that time, and advanced to the throne.
The vision was this. When Ethelfrid, his predecessor, was persecuting him, he wandered for many years as an exile, hiding in divers places and kingdoms, and at last came to Redwald, beseeching him to give him protection against the snares of his powerful persecutor. Redwald willingly received him, and promised to perform 'what was asked of him. But when Ethelfrid understood that he had appeared in that province, and that he and his companions were hospitably entertained by Redwald, he sent messengers to bribe that king with a great sum of money to murder him, but without effect. He sent a second and a third time, offering a greater bribe each time, and, moreover, threatening to make war on him if his offer should be despised. Redwald, whether terrified by his threats, or won over by his gifts, complied with this request, and promised either to kill Edwin, or to deliver him up to the envoys. A faithful friend of his, hearing of this, went into his chamber, where he was going to bed, for it was the first hour of the night; and calling him out, told him what the king had promised to do with him, adding, "If, therefore, you are willing, I will this very hour conduct you out of this province, and lead you to a place where neither Redwald nor Ethelfrid shall ever find you." He answered, "I thank you for your good will, yet I cannot do what you propose, and be guilty of being the first to break the compact I have made with so great a king, when he has done me no harm, nor shown any enmity to me; but, on the contrary, if I must die, let it rather be by his hand than by that of any meaner man. For whither shall I now fly, when I have for so many long years been a vagabond through all the provinces of Britain, to escape the snares of my enemies?" His friend went away; Edwin remained alone without, and sitting with a heavy heart before the palace, began to be overwhelmed with many thoughts, not knowing what to do, or which way to turn.
When he had remained a long time in silent anguish of mind, consumed with inward fire, on a sudden in the stillness of the dead of night he saw approaching a person, whose face and habit were strange to him, at sight of whom, seeing that he was unknown and unlooked for, he was not a little startled. The stranger coming close up, saluted him, and asked why he sat there in solitude on a stone troubled and wakeful at that time, when all others were taking their rest, and were fast asleep. Edwin, in his turn, asked, what it was to him, whether he spent the night within doors or abroad. The stranger, in reply, said, "Do not think that I am ignorant of the cause of your grief, your watching, and sitting alone without. For I know of a surety who you are, and why you grieve, and the evils which you fear will soon fall upon you. But tell me, what reward you would give the man who should deliver you out of these troubles, and persuade Redwald neither to do you any harm himself, nor to deliver you up to be murdered by your enemies." Edwin replied, that he would give such an one all that he could in return for so great a benefit. The other further added, "What if he should also assure you, that your enemies should be destroyed, and you should be a king surpassing in power, not only all your own ancestors, but even all that have reigned before you in the English nation?" Edwin, encouraged by these questions, did not hesitate to promise that he would make a fitting return to him who should confer such benefits upon him. Then the other spoke a third time and said, "But if he who should truly foretell that all these great blessings are about to befall you, could also give you better and more profitable counsel for your life and salvation than any of your fathers or kindred ever heard, do you consent to submit to him, and to follow his wholesome guidance?" Edwin at once promised that he would in all things follow the teaching of that man who should deliver him from so many great calamities, and raise him to a throne.
Having received this answer, the man who talked to him laid his right hand on his head saying, "When this sign shall be given you, remember this present discourse that has passed between us, and do not delay the performance of what you now promise." Having uttered these words, he is said to have immediately vanished. So the king perceived that it was not a man, but a spirit, that had appeared to him.
Whilst the royal youth still sat there alone, glad of the comfort he had received, but still troubled and earnestly pondering who he was, and whence he came, that had so talked to him, his aforesaid friend came to him, and greeting him with a glad countenance, "Rise," said he, "go in; calm and put away your anxious cares, and compose yourself in body and mind to sleep; for the king's resolution is altered, and he designs to do you no harm, but rather to keep his pledged faith; for when he had privately made known to the queen his intention of doing what I told you before, she dissuaded him from it, reminding him that it was altogether unworthy of so great a king to sell his good friend in such distress for gold, and to sacrifice his honour, which is more valuable than all other adornments, for the love of money." In short, the king did as has been said, and not only refused to deliver up the banished man to his enemy's messengers, but helped him to recover his kingdom. For as soon as the messengers had returned home, he raised a mighty army to subdue Ethelfrid; who, meeting him with much inferior forces, (for Redwald had not given him time to gather and unite all his power,) was slain on the borders of the kingdom of Mercia, on the east side of the river that is called Idle. In this battle, Redwald's son, called Raegenheri, was killed. Thus Edwin, in accordance with the prophecy he had received, not only escaped the danger from his enemy, but, by his death, succeeded the king on the throne.
King Edwin, therefore, delaying to receive the Word of God at the preaching of Paulinus, and being wont for some time, as has been said, to sit many hours alone, and seriously to ponder with himself what he was to do, and what religion he was to follow, the man of God came to him one day, laid his right hand on his head, and asked, whether he knew that sign? The king, trembling, was ready to fall down at his feet, but he raised him up, and speaking to him with the voice of a friend, said, "Behold, by the gift of God you have escaped the hands of the enemies whom you feared. Behold, you have obtained of His bounty the kingdom which you desired. Take heed not to delay to perform your third promise; accept the faith, and keep the precepts of Him Who, delivering you from temporal adversity, has raised you to the honour of a temporal kingdom; and if, from this time forward, you shall be obedient to His will, which through me He signifies to you, He will also deliver you from the everlasting torments of the wicked, and make you partaker with Him of His eternal kingdom in heaven."