ذَٰلِكُم بِمَا كُنتُمْ تَفْرَحُونَ فِى ٱلْأَرْضِ بِغَيْرِ ٱلْحَقِّ وَبِمَا كُنتُمْ تَمْرَحُونَ
That is because you exulted in the land unjustly and because you behaved insolently.