Sayyiduna Sa'd bin Junadah (may Allah be pleased with him) said: I came to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) taught me the surahs "Idha zulzilat", "Qul ya ayyuha al-kafirun" and "Qul huwa Allahu ahad", and he taught me these words: Subhan Allah (Glory be to Allah), wal-hamdu lillah (and praise be to Allah), wa la ilaha illa Allah (and there is no god but Allah), wa Allahu akbar (and Allah is the Greatest); and he said: "These are al-baqiyat al-salihat (the enduring good deeds)."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5463