Surah Yunus, ayah 36

وَمَا يَتَّبِعُ أَكۡثَرُهُمۡ إِلَّا ظَنًّاۚ إِنَّ ٱلظَّنَّ لَا يُغۡنِي مِنَ ٱلۡحَقِّ شَيۡـًٔاۚ إِنَّ ٱللَّهَ عَلِيمُۢ بِمَا يَفۡعَلُونَ ٣٦

Wamā yattabi'u aktharuhum illā zannan innaz-zanna lā yughnī minal-haqqi shay'an innallāha 'alīmu bimā yaf'alūn

And most of them follow not except assumption. Indeed, assumption avails not against the truth at all. Indeed, Allāh is Knowing of what they do.