Then by the Lord of the heaven and earth, indeed, it is truth - just as [sure as] it is that you are speaking.
The Saheeh International Quran Translation
فَوَرَبِّ ٱلسَّمَآءِ وَٱلْأَرْضِ إِنَّهُۥ لَحَقٌّ مِّثْلَ مَآ أَنَّكُمْ تَنطِقُونَThen by the Lord of the heaven and earth, indeed, it is truth - just as [sure as] it is that you are speaking.