Musnad Abu Ya'la al-Mawsili 42:411

On the authority of Abu Sa’id, from the Messenger of Allah (may Allah bless him and grant him peace), he said: "Increase in the enduring righteous deeds." It was said: "And what are they, O Messenger of Allah?" He said: "The creed (al-millah)." It was said: "And what is it, O Messenger of Allah?" He said: "The declaration of the oneness of Allah (tahlil), the declaration of the greatness of Allah (takbir), the declaration of the perfection of Allah (tasbih), praise be to Allah (al-hamdu lillah), and there is no power and no strength except by Allah."