Quran 21:57 from Surah Al-Anbiyaa on Divine Marvels.
وَتَٱللَّهِ لَأَكِيدَنَّ أَصۡنَٰمَكُم بَعۡدَ أَن تُوَلُّواْ مُدۡبِرِينَ
English translation: And by Allah surely I will plan (against) your idols after [that] you go away turning (your) backs
Transliteration: watal-lahi la-akidanna asnamakum ba'da an tuwallu mud'birina