وَإِن مِّن شَيْءٍ إِلَّا عِندَنَا خَزَائِنُهُ وَمَا نُنَزِّلُهُ إِلَّا بِقَدَرٍ مَّعْلُومٍ

There is not a thing but that its sources are with Us, and We do not send it down except in a known measure.