that was because their apostles would bring them manifest proofs but they said will humans be our guides?! so they disbelieved and turned away and allah had no need and allah is allsufficient alllaudable.
ذلك بأنه كانت تأتيهم رسلهم بالبينات فقالوا أبشر يهدوننا فكفروا وتولوا واستغنى الله والله غني حميد