أَلَمْ تَرَ أَنَّ اللَّهَ يُزْجِي سَحَابًا ثُمَّ يُؤَلِّفُ بَيْنَهُ ثُمَّ يَجْعَلُهُ رُكَامًا فَتَرَى الْوَدْقَ يَخْرُجُ مِنْ خِلَالِهِ وَيُنَزِّلُ مِنَ السَّمَاءِ مِن جِبَالٍ فِيهَا مِن بَرَدٍ فَيُصِيبُ بِهِ مَن يَشَاءُ وَيَصْرِفُهُ عَن مَّن يَشَاءُ ۖ يَكَادُ سَنَا بَرْقِهِ يَذْهَبُ بِالْأَبْصَارِ (43)
(24:43) Do you not observe that Allah makes the cloud move gently then joins its pieces together: then gathers it into a mass of thick cloud: then you see that rain-drops fall down from its midst: and He sends down hail out of the high up mountains in the heaven: *75 then He smites with it whom He wills and turns it away from whom He pleases: then a flash of lightning from it dazzles the eyes.
*75) This may mean frozen clouds which have been called `mountains in the heavens' metaphorically. It may also mean the mountains of the earth which stand high in the heavens and whose snow-capped peaks cause condensation in the clouds which results in hailstorms.