Whatever Allah 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.
مَا يَفْتَحِ اللَّهُ لِلنَّاسِ مِنْ رَحْمَةٍ فَلَا مُمْسِكَ لَهَا ۖ وَمَا يُمْسِكْ فَلَا مُرْسِلَ لَهُ مِنْ بَعْدِهِ ۚ وَهُوَ الْعَزِيزُ الْحَكِيمُ
Yahya related to me from Malik that he had heard that Abu Hurayra used to say, when morning came after it had rained on the people, "We have been rained upon by the rain of Allah's opening," and would then recite the ayat, "Whatever Allah opens to man of His mercy no-one can withhold, and whatever He withholds no-one can send forward after Him. " (Sura 35 ayat 2).
أَنَّ أَبَا هُرَيْرَةَ كَانَ يَقُولُ إِذَا أَصْبَحَ وَقَدْ مُطِرَ النَّاسُ مُطِرْنَا بِنَوْءِ الْفَتْحِ ثُمَّ يَتْلُو هَذِهِ الآيَةَ مَا يَفْتَحِ اللَّهُ لِلنَّاسِ مِنْ رَحْمَةٍ فَلاَ مُمْسِكَ لَهَا وَمَا يُمْسِكْ فَلاَ مُرْسِلَ لَهُ مِنْ بَعْدِهِ