﴿ وَإِن مِّن شَىْءٍ إِلَّا عِندَنَا خَزَآئِنُهُۥ وَمَا نُنَزِّلُهُۥٓ إِلَّا بِقَدَرٍۢ مَّعْلُومٍۢ ﴾

“For, no single thing exists that does not have its source with Us; and nought do We bestow from on high unless it be in accordance with a measure well-defined.”

Please check ayah 15:25 for complete tafsir.