http://www.dhikrullah.com/blog/?p=203

The Prophet SAW said in a hadeeth qudsi; Allah [aza wajal] said,
‘Spend (O man), and I shall spend on you.” [Bukhari]


If you spend in this dunya, Allah aza wajal will spend on you and repay you not only in this world but in the hereafter inshaAllah. The money that you have acquired is but only through Allah’s blessing and provision, so why not be thankful for the provision Allah has given you by spending for the sake of Allah. The more you spend for the sake of Allah, the more Allah will spend on you..