Surah 92. Al-Lail, Ayah 18

The spending may be for charity, or for good works, such as advancing the cause of knowledge or science, or supporting ideals, etc. "Wealth" must be understood not only for money or material goods, but also for any advantage or opportunity which a man happens to enjoy, and which he can place at the service of others.

The Arabic root word zaka implies both increase and purification, and both meanings may be understood to be implied here. Wealth (understood both literally and metaphorically) is not for selfish enjoyment or idle show. It is held on trust. It may be a trial in itself, from which a man who emerges successfully is a man all the purer in his life; and even if he was a good man before, his proper use of his wealth increases his position and dignity in the moral and spiritual world.