An-Najm 28

وَمَا لَهُم بِهِۦ مِنْ عِلْمٍ ۖ إِن يَتَّبِعُونَ إِلَّا ٱلظَّنَّ ۖ وَإِنَّ ٱلظَّنَّ لَا يُغْنِى مِنَ ٱلْحَقِّ شَيْـًٔا

wamā lahum bihi min ʿil'min in yattabiʿūna illā l-ẓana wa-inna l-ẓana lā yugh'nī mina l-ḥaqi shayan

And they have thereof no knowledge. They follow not except assumption, and indeed, assumption avails not against the truth at all.