Musnad Ahmad 30:974

'Abd al-Razzaq narrated to us, Isra'il informed us, from Abu Sinan, from Abu Salih al-Hanafi, from Abu Sa'id al-Khudri and Abu Hurayrah, from the Prophet (peace and blessings of Allah be upon him), who said: "Indeed, Allah the Almighty has chosen four phrases of speech: *Subhan Allah* (Glory be to Allah), *Al-hamdu lillah* (Praise be to Allah), *La ilaha illa Allah* (There is no god but Allah), and *Allahu Akbar* (Allah is the Greatest)." He said: "Whoever says *Subhan Allah*, twenty good deeds are written for him, and twenty evil deeds are removed from him. Whoever says *Allahu Akbar*, it is the same as that. Whoever says *La ilaha illa Allah*, it is the same as that. And whoever says *Al-hamdu lillahi Rabb al-'alamin* (Praise be to Allah, Lord of the worlds) from his own self, thirty good deeds are written for him by it, and thirty evil deeds are removed from him by it."