that was because there came to them their messengers with clear proofs but they said shall mere men guide us? so they disbelieved and turned away and allah was not in need . and allah is rich worthy of all praise.
ذلك بأنه كانت تأتيهم رسلهم بالبينات فقالوا أبشر يهدوننا فكفروا وتولوا واستغنى الله والله غني حميد