Falling rain states monotheism and Resurrection
As it is mentioned in the Koran, falling rain and reviving nature states monotheism and Resurrection:
God is the one who sends the winds to blow the clouds along. He spreads them out in the sky just as He wishes, and breaks them up into patches so you see a shower coming from inside them. When he strikes any of His servants whom he wishes with it, they are overjoyed, even if before it fell on them, they had felt disheartened.
Look at the traces of God's mercy; how He revives the earth following its death, such is the Reviver from the dead, He is capable of everything!
Even if we sent a wind so they might see it turning things yellow, they would still keep on disbelieving even after it. (30:48-51)
Sources :
al-Mizan (Allameh Tabatabai)
The Quran English translation (T.B. Irving)
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