وَلاَ يَحْسَبَنَّ الَّذِينَ كَفَرُواْ أَنَّمَا نُمْلِي لَهُمْ خَيْرٌ لِّأَنفُسِهِمْ {And let not those who disbelieve ever think that [because] We extend their time [of enjoyment] it is better for them.}: Those who were not killed, and those who believe that they won in the Battle of Uhud are mistaken. This is to give rest to the Prophet (saws), and to the believers:

إِنَّمَا نُمْلِي لَهُمْ لِيَزْدَادُواْ إِثْمًا {We only extend it for them so that they may increase in sin}: meaning that Allah (swt) extend it for them to increase in sin, and the result is they will have a humiliating torment. Of course, when Allah (swt) uses a different description of the torment, He says once: It is a great punishment, and another: It is a painful torment, or: a humiliating torment, they are not just expressions, rather they differ in their connotations, and what is meant here is that a person is tormented while he is in a state of humiliation in front of his followers, so every word has its intended meaning.