﴿ مِن قَبْلُ هُدًۭى لِّلنَّاسِ وَأَنزَلَ ٱلْفُرْقَانَ ۗ إِنَّ ٱلَّذِينَ كَفَرُوا۟ بِـَٔايَٰتِ ٱللَّهِ لَهُمْ عَذَابٌۭ شَدِيدٌۭ ۗ وَٱللَّهُ عَزِيزٌۭ ذُو ٱنتِقَامٍ ﴾

“aforetime, as a guidance unto mankind, and it is He who has bestowed [upon man] the standard by which to discern the true from the false. Behold, as for those who are bent on denying God's messages - grievous suffering awaits them: for God is almighty, an avenger of evil.”

�and He revealed the criterion�That is, the Qurʾān, wherein is the way out of all doubt and error.