سورة Al-Baqarah ( The Cow ) - الآية 265

In contrast to them, the charity of those, who expend their wealth sincerely with the sole desire of pleasing Allah, may be likened to a garden on a plateau. If heavy rain falls, it yields its produce twofold: and even if there is no heavy rain but only a light shower, that too, is sufficient for it: whatever you do is in the sight of Allah.