the desert arabs are more stubborn in their denial of truth and hypocrisy and are the least likely to be aware of the limits which god has revealed to his messenger. god is all knowing and wise.
الأعراب أشد كفرا ونفاقا وأجدر ألا يعلموا حدود ما أنزل الله على رسوله والله عليم حكيم