Sahih Muslim Book 5, Hadith Number 2246.

Chapter : Exhortation to give charity even though it is small; (the one who gives) small amount should neither be discouraged not looked down upon.

Asma’, daughter of Abu Bakr, reported that abe came to the Apostle of Allah (may peace he upon him) and said: Apostle of Allah, I have nothing with me, but only, that which is given to me by Zubair (for household expenses). Is there any sin for me if I spend out of that which is given to me (by Zabair)? Upon this he (the Holy Prophet) said: Spend according to your means; and do not hoard, for Allah will withhold from you.