Adh-Dhariyat 23

فَوَرَبِّ ٱلسَّمَآءِ وَٱلْأَرْضِ إِنَّهُۥ لَحَقٌّ مِّثْلَ مَآ أَنَّكُمْ تَنطِقُونَ

fawarabbi l-samāi wal-arḍi innahu laḥaqqun mith'la mā annakum tanṭiqūna

Then by the Lord of the heaven and earth, indeed, it is truth - just as [sure as] it is that you are speaking.