Musannaf Ibn Abi Shayba 3:5727

Hushaym narrated to us, he said: Al-Fadl ibn Atiyyah informed us, he said: Someone who saw Urwah ibn al-Zubayr informed me, while he was praying and saying: "O Allah, forgive al-Zubayr. O Allah, forgive Asma bint Abi Bakr."