"Those before them denied," meaning: before your people, O Muhammad.
"So the torment came upon them from where they did not perceive," it came upon them suddenly.
﴿كذب الَّذين من قبلهم﴾ يَعْنِي: من قبل قَوْمك يَا محمدُ.
﴿فَأَتَاهُمُ الْعَذَابُ مِنْ حَيْثُ لَا يَشْعُرُونَ﴾ جَاءَهُم فَجْأَة
