They had no knowledge about this; they only conjectured. Conjecture is no substitute for the truth.
وَما لَهُم بِهِ مِن عِلمٍ إِن يَتَّبِعونَ إِلَّا الظَّنَّ وَإِنَّ الظَّنَّ لا يُغنى مِنَ الحَقِّ شَيـًٔا
wa maa lahum bihee min ‘ilmin iny yattabi’oona illaz zanna wa innaz zanna laa yughnee minal haqqi shai’aa