The Thunder - 13:26 Allah increases or decreases provision for whom He wills. They rejoice in the life of this world, while the life of this world is but a subsistence compared to the Hereafter.
Why does Allah increase or decrease provision for whom He wills?
The Dawn/89:15 "When his Lord gives to man abundantly to test him, he says: "My Lord has been generous to me"."
The Dawn/89:16 "But when his Lord tests him by withholding his sustenance, he says, "My Lord has humiliated me."