Musannaf Ibn Abi Shayba 21:608

Hussain bin Ali al-Ju'fi narrated to us, from Isra'il, from Ziyad, from Mis'ar, from al-Hasan, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said to Abu Bakr: "Shall I not guide you to a charity that fills what is between the heaven and the earth? [Say:] 'Subhan Allah' (Glory be to Allah), 'al-Hamdulillah' (Praise be to Allah), 'la ilaha illallah' (There is no god but Allah), 'wa Allahu Akbar' (And Allah is the Greatest), 'wa la hawla wa la quwwata illa billah' (And there is no power and no strength except by Allah), thirty times a day."