There was a certain harlot called Thaïs and she was so beautiful that many for her sake sold all that they had and reduced themselves to utter poverty; quarrels arose among her lovers, and often the doorstep of this girl’s house was soaked in the blood of young men.
When Abba Paphnutius heard about it, he put on normal clothes and went to see her in a certain city in Egypt. He handed her a silver piece as the price for committing sin. She accepted the price and said, “Let us go inside.” When he went in, he sat down on the bed which was draped with precious covers and he invited her, saying, “If there is a more private chamber, let us go in there.” She said, “There is one, but if it is people you are afraid of, no one ever enters this room, except, of course, for God, for there is no place that is hidden from the eyes of divinity.” When the old man heard this, he said to her, “So you know there is a God?” She answered him, “I know about God and about the eternal kingdom and also about the future torments of sinners.” “But if you know this,” he said, “why are you causing the loss of so many souls so that you will be condemned to render an account not only of your own sins but of theirs as well?”
When Thaïs heard this, she threw herself at the feet of Paphnutius and begged him with tears, “Give me a penance, Father, for I trust to find forgiveness by your prayers. I beg you to wait for just three hours, and after that, wherever you tell me to go, I will go, and whatever you tell me to do, I will do it.” So Paphnutius arranged a meeting place with her and she went out and collected together all the goods that she had received by her sins and piled them all together in the middle of the city, while all the people watched, saying, “Come here, all of you that have sinned with me, and see how I am burning whatever you gave me.”
When it was all consumed, she went to the place that the Father had arranged with her. Then he sought out a monastery of virgins and took her into a small cell, sealing the door with lead and leaving only a small opening through which food could be passed to her and he ordered her to be given daily a little bread and a little water by the sisters of the monastery. When Thaïs realized that that the door was sealed with lead, she said to him, “Father, where do you want me to urinate?” and he replied, “in the cell, as you deserve.” Then she asked him how she should pray to God, and he said to her, “You are not worthy to name God, or to take his divine name upon your lips, or to lift up your hands to heaven, for your lips are full of sin and your hands are stained with iniquity; only stand facing toward the east and repeat often only this: “You who made me, have mercy upon me.”
Benedicta Ward, Harlots of the Desert: A Study of Repentance in Early Monastic Sources (Oxford: A.R. Mowbray, 1987), pp. 83-84 - this is a Christian story that originated among circles of Egyptian monks during the fourth or fifth century C.E.