وَمَثَلُ الَّذِيْنَ يُنْفِقُوْنَ اَمْوَالَهُمُ ابْتِغَاۤءَ مَرْضَاتِ اللّٰهِ وَتَثْبِيْتًا مِّنْ اَنْفُسِهِمْ كَمَثَلِ جَنَّةٍۢ بِرَبْوَةٍ اَصَابَهَا وَابِلٌ فَاٰتَتْ اُكُلَهَا ضِعْفَيْنِۚ فَاِنْ لَّمْ يُصِبْهَا وَابِلٌ فَطَلٌّ ۗوَاللّٰهُ بِمَا تَعْمَلُوْنَ بَصِيْرٌ ( البقرة: ٢٦٥ )
Wa masalul lazeena yunfiqoona amwaalahumub ti ghaaaa'a mardaatil laahi wa tasbeetam min anfusihim kamasali jannatim birabwatin asaabahaa waabilun fa aatat ukulahaa di'faini fa il lam yusibhaa waabilun fatall; wallaahu bimaa ta'maloona Baseer (al-Baq̈arah 2:265)
And the example of those who spend their wealth seeking means to the approval of Allah and assuring [reward for] themselves is like a garden on high ground which is hit by a downpour – so it yields its fruits in double. And [even] if it is not hit by a downpour, then a drizzle [is sufficient]. And Allah, of what you do, is Seeing. (Al-Baqarah  : 265)
1 Mufti Taqi Usmani
The example of those who spend their wealth to seek the pleasure of Allah and to make firm (their faith) from (the depths of) their souls is like a garden on a foothill on which came a heavy rain, and it yielded its produce twofold. Even if a heavy rain does not come to it, a light drizzle is enough, and Allah is watchful of what you do.