Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
THE place is shown to this day, and held in much veneration, where Oswald, being about to engage in this battle, erected the symbol of the Holy Cross, and knelt down and prayed to God that he would send help from Heaven to his worshippers in their sore need. Then, we are told, that the cross being made in haste, and the hole dug in which it was to be set up, the king himself, in the ardour of his faith, laid hold of it and held it upright with both his hands, till the earth was heaped up by the soldiers and it was fixed. Thereupon, uplifting his voice, he cried to his whole army, "Let us all kneel, and together beseech the true and living God Almighty in His mercy to defend us from the proud and cruel enemy; for He knows that we have undertaken a just war for the safety of our nation." All did as he had commanded, and accordingly advancing towards the enemy with the first dawn of day, they obtained the victory, as their faith deserved. In the place where they prayed very many miracles of healing are known to have been wrought, as a token and memorial of the king’s faith; for even to this day, many are wont to cut off small splinters from the wood of the holy cross, and put them into water, which they give to sick men or cattle to drink, or they sprinkle them therewith, and these are presently restored to health.
The place is called in the English tongue Hefenfelth, or the Heavenly Field,which name it undoubtedly received of old as a presage of what was afterwards to happen, denoting, that the heavenly trophy was to be erected, the heavenly victory begun, and heavenly miracles shown forth to this day. The place is near the wall in the north which the Romans formerly drew across the whole of Britain from sea to sea, to restrain the onslaught of the barbarous nations, as has been said before. Hither also the brothers of the church of Hagustald, which is not far distant, long ago made it their custom to resort every year, on the day before that on which King Oswald was afterwards slain, to keep vigils there for the health of his soul, and having sung many psalms of praise, to offer for him in the morning the sacrifice of the Holy Oblation. And since that good custom has spread, they have lately built a church there, which has attached additional sanctity and honour in the eyes of all men to that place;and this with good reason; for it appears that there was no symbol of the Christian faith, no church, no altar erected throughout all the nation of the Bernicians, before that new leader in war, prompted by the zeal of his faith, set up this standard of the Cross as he was going to give battle to his barbarous enemy.
Nor is it foreign to our purpose to relate one of the many miracles that have been wrought at this cross. One of the brothers of the same church of Hagulstald, whose name is Bothelm, and who is still living, a few years ago, walking carelessly on the ice at night, suddenly fell and broke his arm; he was soon tormented with a most grievous pain in the broken part, so that he could not lift his arm to his mouth for the anguish. Hearing one morning that one of the brothers designed
to go up to the place of the holy cross, he desired him, on his return to bring him a piece of that sacred wood, saying, he believed that with the mercy of God he might thereby be healed. The brother did as he was desired; and returning in the evening, when the brothers were sitting at table, gave him some of the old moss which grew on the surface of the wood. As he sat at table, having no place to bestow the gift which was brought him, he put it into his bosom; and forgetting, when he went to
bed, to put it away, left it in his bosom. Awaking in the middle of the night, he felt something cold lying by his side, and putting his hand upon it to feel what it was, he found his arm and hand as sound as if he had never felt any such pain.