Musnad Abu Ya'la al-Mawsili 154:117

Ahmad ibn Ibrahim al-Dawraqi narrated to us, Muhammad ibn Kathir narrated to us, from al-Awza'i, from Nuhayk ibn Yuraym, from Mughith ibn Sumayy, who said: Abdullah ibn al-Zubayr led us in prayer in the darkness of the end of the night, and Ibn Umar was at my side. When he finished the prayer, I said, "What is this prayer, O Abu Abd al-Rahman?" He said, "This was our prayer with the Messenger of Allah (may Allah bless him and grant him peace), and with Abu Bakr and Umar. But when Umar was killed, Uthman began to perform it when it was brighter."