Hardness of hearts and disbelief

فَأَخَذَهُمُ ٱلْعَذَابُ ۗ إِنَّ فِى ذَٰلِكَ لَـَٔايَةً ۖ وَمَا كَانَ أَكْثَرُهُم مُّؤْمِنِينَ

And the punishment seized them. Indeed in that is a sign, but most of them were not to be believers.