"Are your disbelievers," meaning the people of Mecca, "better than those," meaning your people from the past nations? That is, they are not better than them. It means: they were stronger than them in power and more numerous in wealth and children. "Or have you a guarantee," meaning: against the punishment, "in the scriptures," meaning in the books.
﴿أكفاركم﴾ يَعْنِي أهل مَكَّة ﴿خَيْرٌ مِنْ أولئكم﴾ يَعْنِي: مِنْ أُهْلِكَ مِنَ الْأُمَمِ السالفة، أَي: لَيْسُوا بِخَير مِنْهُم، يَعْنِي: كَانُوا أَشد مِنْهُم قُوَّة وَأكْثر أَمْوَالًا وأولادًا ﴿أَمْ لَكُمْ بَرَاءَة﴾ أَي: من الْعَذَاب ﴿فِي الزُّبُرِ﴾ فِي الْكتب