Musnad Ahmad 30:3680

Abdullah ibn Yazid narrated to us, al-Mas'udi narrated to us, 'Alqamah ibn Marthad narrated to us, from Abu al-Rabi', from Abu Hurairah, that the Prophet, peace and blessings of Allah be upon him, used to supplicate: "O Allah, forgive me for what I have sent forth and what I have delayed, and what I have kept secret and what I have made public, and my extravagance, and that which You know better than I do. You are the Advancer and You are the Delayer. There is no god but You."