Quran 26:97 from Surah Ash-Shu'araa on Divine Marvels.
تَٱللَّهِ إِن كُنَّا لَفِي ضَلَٰلٖ مُّبِينٍ
English translation: By Allah indeed we were surely in error clear
Transliteration: tal-lahi in kunna lafi dalalin mubinin