In the Quran

لَهُۥ مُعَقِّبَٰتٞ مِّنۢ بَيۡنِ يَدَيۡهِ وَمِنۡ خَلۡفِهِۦ يَحۡفَظُونَهُۥ مِنۡ أَمۡرِ ٱللَّهِۗ إِنَّ ٱللَّهَ لَا يُغَيِّرُ مَا بِقَوۡمٍ حَتَّىٰ يُغَيِّرُواْ مَا بِأَنفُسِهِمۡۗ وَإِذَآ أَرَادَ ٱللَّهُ بِقَوۡمٖ سُوٓءٗا فَلَا مَرَدَّ لَهُۥۚ وَمَا لَهُم مِّن دُونِهِۦ مِن وَالٍ

"For each one are successive [angels] before and behind him who protect him by the decree of Allah. Indeed, Allah will not change the condition of a people until they change what is in themselves. And when Allah intends for a people ill, there is no repelling it. And there is not for them besides Him any patron"