From: Jewish Folktales. Selected and Retold by Pinhas Sadeh. Translated from the Hebrew by Hillel Halkin, An Anchor Book, Published by Doubleday, New York, 1989, p. 195-197

Once, long ago, the was a very wealthy and upright Jew who had no children. When he was sixty years old, his wife died, and soon several matchmakers came to him and sought with weighty words to persuade him to remarry. The members of his family were opposed to this, as they wished to be his sole heirs, but he had a poor brother, the father of an unmarried daughter, who cunningly strove to marry her to her rich uncle and in the end, succeeded. The man married his niece and lived with her for several years, during which he again had no children. This made him realize that he himself must be the cause of his childlessness.

And so, when one day the man's wife conceived, he knew at once that she carried another man's illegitimate child. In private he revealed this fact to the rabbi of Vilna, who was a most wise and learned man; but when a male child was born, not wishing to make it known that the boy was a bastard, he pretended to be delighted and even gave a grand banquet on the day of the circumcision, as was expected of a wealthy man like himself. The circumcision was done by the rabbi, who alone knew the truth -- and who secretly performed a vasectomy too, for a bastard's children are also illegitimate, and he wished to put an end to bastardy.
No one knew about this; yet when the circumcision was over, the rabbi openly cut the child's ear with his knife -- and when asked the reason, he replied that he was giving the boy a special sign because he was so precious to his parents.

Time passed, the rich Jew died, and his wife inherited his fortune. Meanwhile, the boy grew up and excelled so much in his studies that he was the outstanding pupil in Vilna and could carry on a lively debate with Talmud scholars much older than himself. In fact, he so trounced them and put them to shame that they took to calling him 'the little bastard!' Eventually, the rumor spread that he really was one, and one day he came bitterly to his mother, told her of this epithet, and asked for some money to travel, since he could not stand the disgrace any longer and would gladly forfeit his share of his father's estate in order to get away. His mother gave him what he asked for, and he journeyed to a distant town, where there happened to be a large Talmud academy. Enrolling in it, he did so well that he soon was the prize student.

Now in the city of Rome lived a wealthy, charitable, and God-fearing Jew who had an only daughter. One day he traveled to this academy to look for a husband for her, saw the young man, was impressed by everything about him, and chose him for his son-in-law. (The youngster did not reveal that he hailed from Vilna, simply saying that he came from far away). And so the student married the young lady and was soon a favorite of Rome, for no Jewish youth in the city could compare to him. His father-in-law and mother-in-law doted on him and loved him greatly, though he and their daughter had no children.

Thus, the bridegroom lived in Rome for several years, until one day the rabbi of Vilna, who was traveling from place to place to raise funds for the ransoming of Jewish captives taken by the Turks, arrived in the city. While staying there, he visited several synagogues and gave some wondrously learned sermons -- with each of which, however, the young Talmudist successfully disputed. Finally, on a Sabbath eve, the rabbi prepared a talmudic proof so brilliant that he was sure it was irrefutable; yet when he preached it the next day, he was once again outdebated by his young opponent and, indeed, thoroughly mortified. Needless to say, he had no idea who the young man was.

That Sunday morning, the rabbi set about collecting for his fund. When he came to the rich Jew's house for a contribution, the latter asked him to stay in Rome another week: if , said the man, he would agree to be his guest and continue his debates with his son-in-law, he would be most generously rewarded. The rabbi consented and spent this week too dueling with his young rival -- who again won every bout.

That Saturday evening, when the week was up, the rabbi took a last look at the youngster, noticed the scar on his ear, and realized who he was. At once he took the boy's father-in-law aside and told him the whole story, after which he received his promised contribution and left town. So great were the rich Jew's grief and anxiety, however, that he soon fell ill and took to his bed, and when his son-in-law came to pay a sick call, he told him what the rabbi had said, namely, that he was a bastard and sterile. The young man was so shattered that he agreed on the spot to give his wife a divorce.

Afterward, the illegitimate Talmud student traveled elsewhere and converted to Christianity. He took up the study of Greek and Latin, mastered them in no time, and soon became a priest, then a bishop, then a cardinal, and finally, the pope in Rome.

Following his daughter's divorce, the rich Jew lost track of his former son-in-law. Meanwhile, however, his own fortunes took a turn for the worse. Some enemies of his who were jealous of his wealth hired two policemen to pay poor shoemaker ten ducats for one of his children, whom they then murdered and flung into the rich Jew's yard in order to blame the crime on him. And indeed, the same policemen came the next day, pretended to search the yard, unearthed the corpse, arrested the man, his wife, and his daughter, and threw them all into prison to await the pope's judgment.

When the Jews of Rome heard what had happened to the rich man's family, they stood bail for them, pending the trial. Meanwhile, the pope disguised himself, came to his former father-in-law's house pretending to be a wine buyer (for the man was also a wine merchant), and asked him why he and his family looked so crestfallen. At first the Jew did not want to speak, but after much prompting he told the pope the whole story. The pope listened, said some encouraging words, and departed without revealing who he was.

A few more days went by, and time came for the pope to decide the case. He ordered two huge bonfires built at either end of the city and asked for the dead child's body to be brought to him. (Having studied all the sciences, he knew the art of magic too and had arranged for the corpse to speak.). The body was placed by a bonfire, around which the Romans assembled, and when given the command, it rose and told its story: how the policemen had come to its father the shoemaker, and how they had bought it for ten ducats, and how they had murdered it. At once the pope ordered the policemen and the shoemaker burned at the stake and declared the Jew and his family innocent. Then he went to the second bonfire, cursed the Christian religion, cast himself into the flames in the name of the God of Israel, and perished.