Quran 23:109 from Surah Al-Muminoon on Divine Marvels.
إِنَّهُۥ كَانَ فَرِيقٞ مِّنۡ عِبَادِي يَقُولُونَ رَبَّنَآ ءَامَنَّا فَٱغۡفِرۡ لَنَا وَٱرۡحَمۡنَا وَأَنتَ خَيۡرُ ٱلرَّٰحِمِينَ
English translation: Indeed (there) was a party of My slaves (who) said Our Lord! We believe so forgive us and have mercy on us and You (are) best (of) those who show mercy
Transliteration: innahu kana fariqun min ibadi yaquluna rabbana amanna fa-igh'fir lana wa-ir'hamna wa-anta khayru al-rahimina