Word by Word Analysis

مَّا يَفْتَحِ ٱللَّهُ لِلنَّاسِ مِن رَّحْمَةٍ فَلَا مُمْسِكَ لَهَا ۖ وَمَا يُمْسِكْ فَلَا مُرْسِلَ لَهُۥ مِنۢ بَعْدِهِۦ ۚ وَهُوَ ٱلْعَزِيزُ ٱلْحَكِيمُ 2

Whatever Allāh grants to people of mercy - none can withhold it; and whatever He withholds - none can release it thereafter. And He is the Exalted in Might, the Wise.