Γελάσιος Καισαρείας († 395), Ἐκκλησιαστικὴ Ἱστορία:
During the same time Helen, the mother of Constantine—a woman of incomparable faith, inner devotion, and singular magnificence, whose son Constantine truly was and was believed to be—being advised by divine visions, sought out Jerusalem and there inquired diligently of the local inhabitants after the place in which the sacred body of Christ had hung nailed on the cross. It was difficult to find, because a statue of Venus had been set up there by the ancient persecutors, so that if any of the Christians should wish to worship Christ in that place, he would seem to be worshipping Venus. And because of this the place was unfrequented and nearly consigned to oblivion. But when, as we said above, the devout woman had hastened to the place indicated to her by a divine sign, tearing down all the profane and polluted structures, after the rubble had been cleared away, deep down she found three crosses jumbled together.3 But the gladness of having found the object was disturbed by the uncertain identity of each of the crosses. To be sure, that inscription was also there which had been drawn up by Pilate in Greek and Latin and Hebrew letters, but even it did not reveal clearly enough the signs of the dominical cross. At this point the uncertainty of human ambiguity called for divine testimony.
But that most wise and truly divine Macarius, the president of that church, solved the perplexity by the following means. He saw to it that the pieces of wood were brought near to a woman of the highest nobility of that city, who was oppressed by a long illness and facing death, and he made known the efficacy of the salvific cross, making a prayer of this sort to God: bending his knees next to the woman’s bed he cried out in a loud voice, while the God-beloved Helen and a crowd of many people were also present with him. “Do you, master God almighty, who through your only-begotten child Jesus Christ wrought salvation for humankind on the tree of the cross, who also now at the end of times have inspired your maidservant along with her child, your manservant,6 to search for the blessed tree, on which the savior of all people (especially the faithful), Christ, was nailed in the flesh: show to us, Lord, which of these three trees is the cross of Christ, the one that, through its being pressed by us on this ill and half-dead woman, leads her by the hand to health and resurrection.”
So when he had finished praying, he carried forward the first piece of wood and placed it on the patient, but it did not profit her at all. Then he brought forward the second one too, but it also was shown to be ineffective. Now when he reached out his hand to the third one in turn, the wood approached the ill woman by its shadow and a great wonder occurred. For the half-dead woman suddenly opened her eyes and then, when he placed the precious and dominical cross upon her, she immediately jumped up, stood on her feet, and sent up glory to God. Having become so much better than she had previously been and running around her entire house and rejoicing, with a loud voice she declared the good tidings of the power of the divine cross together with all her household. Thus the most pious empress, the mother of the most praiseworthy and most God-beloved emperor Constantine, having wholly fixed her mind on the matter and proven the identity of the salvific tomb and the precious cross of Christ, immediately erected a house of prayer in that place according to the orders of her most pious child Constantine. And having designated it a martyrium, she advanced thenceforth more and more in faith.
Gelasius of Caesarea Ecclesiastical History, The Extant Fragments With an Appendix containing the Fragments from Dogmatic Writings.
Edited by Martin Wallraff, Jonathan Stutz, Nicholas Marinides. Translated by Nicholas Marinides