سورة Al-Baqarah ( The Cow ) - الآية 273

(Alms are) for the poor who are confined in the way of Allah-- they cannot go about in the land; the ignorant man thinks them to be rich on account of (their) abstaining (from begging); you can recognise them by their mark; they do not beg from men importunately; and whatever good thing you spend, surely Allah knows it.