Musannaf Ibn Abi Shayba 19:454

Abu Bakr narrated to us, he said: Kathir ibn Hisham narrated to us, from Ja'far ibn Burqan, he said: It reached us that a slave girl who was between two men was brought to Umar ibn Abd al-Aziz, and one of them had intercourse with her. He consulted Sa'id ibn al-Musayyib and Urwah ibn al-Zubayr regarding her. They both said: "We are of the opinion that he should be lashed with less than the prescribed punishment (hadd), and they should appraise her value, then he should pay his partner half of the value."