Musannaf Ibn Abi Shayba 9:1566

Abu Bakr narrated to us, he said: Hushaym narrated to us, from Mughira, from Ibrahim, that a man had an orphan girl with him, and she used to attend his food with him. He said: A woman feared that he might marry her instead of her. He said: The man was absent for a period of time, so the woman sought the help of some women against her. They restrained her for her, and she ruined her virginity with her hand. The man returned and began to miss her from his dining table. He said to his wife: "What is the matter with so-and-so? She does not attend my food as she used to attend." She said: "Leave so-and-so alone." He said: "What is the matter with her?" She said: "She has committed adultery." He said: The man went until he entered upon her and said: "What is the matter with you? What is your affair?" He said: She did not do anything but weep. He said: "Tell me." So she told him. He said: He went to Ali, may Allah be pleased with him, and mentioned that to him. He said: He sent for the man’s wife and the women and questioned them. He said: It was not long before they confessed. He said: He then said to al-Hasan: "Judge regarding her." Al-Hasan said: "I see the prescribed punishment (hadd) upon the one who accused her, and the bridal gift (aqr) is upon her, and [the penalty for] the loss of virginity." He said: Ali said: "If you were to task a camel with grinding flour, it would grind it." He said: And no camel was grinding on that day.