Quran 23:90 from Surah Al-Muminoon on Divine Marvels.
بَلۡ أَتَيۡنَٰهُم بِٱلۡحَقِّ وَإِنَّهُمۡ لَكَٰذِبُونَ
English translation: Nay We (have) brought them the truth but indeed they surely (are) liars
Transliteration: bal ataynahum bil-haqi wa-innahum lakadhibuna