Musnad Abu Ya'la al-Mawsili 117:121

Abu Musa narrated to us, Zakariya bin Yahya bin 'Amarah al-Dhari' narrated to us, he said: I heard Thabit narrating from Anas, he said: The Messenger of Allah (peace and blessings of Allah be upon him) used to say on the day of the Trench: "O Allah, were it not for You, we would not have been guided, nor would we have fasted, nor would we have prayed. So send down tranquility upon us."