Quran 23:118 from Surah Al-Muminoon on Divine Marvels.
وَقُل رَّبِّ ٱغۡفِرۡ وَٱرۡحَمۡ وَأَنتَ خَيۡرُ ٱلرَّٰحِمِينَ
English translation: And say My Lord! Forgive and have mercy and You (are the) Best (of) those who show mercy
Transliteration: waqul rabbi igh'fir wa-ir'ham wa-anta khayru al-rahimina