Musannaf Ibn Abi Shayba 18:1106

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Hammad ibn Salamah, from Ibn Abi Mulaykah, that ‘Umar ibn ‘Abd al-‘Aziz and Ibn al-Zubayr executed retaliation (qisas) based on the qasamah (oath-based accusation).