لَا إِلَهَ إِلَّا أَنْتَ سُبْحَانَكَ إِنِّي كُنْتُ مِنَ الظَّالِمِينَ
Transliteration
La ilaha illa anta subhanaka inni kuntu minaz-zalimin
Translation
There is no god but You. Glory be to You! Indeed, I have been among the wrongdoers. (No Muslim supplicates with it for anything except that Allah answers him)
Reference: Quran 21:87, Tirmidhi 3505