Musannaf Ibn Abi Shayba 19:473

Abu Bakr narrated to us, he said: Yazid bin Harun narrated to us, he said: Ibn Abi Arubah narrated to us, from Iyas bin Mu’awiyah, from Nafi’, who said: A slave girl came to Umar and said: "O Commander of the Faithful, Al-Mughirah has intercourse with me, and his wife calls me an adulteress. If I am his, then forbid him from having intercourse with me; and if I am hers, then forbid her from slandering me." So he sent for Al-Mughirah and said: "Do you have intercourse with this slave girl?" He said: "Yes." He asked: "From where?" He said: "My wife gifted her to me." He said: "By Allah, if she had not gifted her to you, you would return to your family stoned." Then he said: "Go to the wife of Al-Mughirah and inform her that if she did not gift her to him, we would stone him." He said: So they went to her and informed her. She said: "Oh, the sorrow! Do you want my husband to be stoned? By Allah, I certainly did gift her to him." He said: So he released him.