'They were more powerful than them,' meaning the polytheists of the Arabs, 'in strength,' that is: in might and power, 'and in the remains they left on earth,' meaning: what they constructed of cities and other remnants of their work, 'but there was for them no protector against Allah' who could shield them from the punishment of Allah.
﴿كَانُوا هم أَشد مِنْهُم﴾ من مُشْركي الْعَرَب ﴿قُوَّة﴾ أَي: بطشًا ﴿وَآثَارًا فِي الأَرْضِ﴾ يَعْنِي: مَا عمِلُوا من الْمَدَائِن وَغَيرهَا من آثَارهم ﴿وَمَا كَانَ لَهُمْ مِنَ اللَّهِ مِنْ وَاقٍ﴾ يقيهم من عَذَاب الله