"And there is not a thing but that with Us are its treasuries," meaning: the rain; and all these things only subsist through rain.
﴿وَإِنْ مِنْ شيءٍ إِلا عِنْدَنَا خزائنه﴾ يَعْنِي: الْمَطَرَ؛ وَهَذِهِ الأَشْيَاءُ كُلُّهَا إِنَّمَا تعيش بالمطر.