The Rocky Tract - 15:21
There is nothing that We do not have its treasures with Us, but We send it down in an appointed measure.
Why does Allah send down everything in a measure?
Council/42:27
If Allah had made the sustenance abundant for His servants, they would have become arrogant in the earth. Indeed, He sends it as He wills. He is All-Knowing, All-Seeing of His servants.