The Qur'an
Malik :: Book 15 : Hadith 15.7.23
Yahya related to me from Malik that Umara ibn Sayyad had heard Said ibn al Musayyab say about abiding good deeds that they were a slave's saying 'Allah is greater' (Allahu akbar) and 'Glory be to Allah' (Subahana'llah) and 'Praise be to Allah' (al-hamdu lillah) and 'There is no god but Allah and there is no power and no strength except by Allah.'
La ilaha illa'llah wa la hawla wa la quwwata illa bi'llah.