Rambam, Mishneh Torah, Laws of Gifts to the Poor 10:7 (cf. Shulchan Aruch, Yoreh Deah, 249: 6-13)

There are eight degrees of tzedakah, each higher than the next. The highest degree, exceeded by none, is that of the person who assists a poor person by providing him with a gift or a loan or by accepting him into a business partnership or by helping him find employment – in a word, by putting him where he can dispense with other people’s aid. With reference to such aid, it is said, “You shall strengthen him, be he a stranger or a settler, he shall live with you” (Leviticus 25:35), which means strengthen him in such a manner that his falling into want is prevented. Below this is that of the person who gives tzedakah to poor people, but the giver doesn’t know to whom he is giving nor does the recipient know from whom he is receiving. This constitutes giving for its own sake. This is similar to the Secret Office that was in the Temple. There the righteous ones gave secretly and the poor people would be sustained from it anonymously. This is similar to giving to a tzedakah collection. But one should only give to a tzedakah collection if he knows that the overseer is trustworthy and wise and conducts himself fairly, like Rabbi Channaniah ben Tradyon. Below this is a situation in which the giver knows to whom he is giving but the poor person does not know from whom he is receiving. This is like the great sages who used to walk in secret and put coins into the doors of poor people. It is worthy and truly good to do this if those who are responsible for collecting tzedakah are not trustworthy. Below this is a situation in which the poor person knows from whom he is receiving, but the giver does not know the recipient. This is like the great sages who used to bundle coins in their scarves and roll them up over their backs and poor people would come and collect without being embarrassed. Below this is one who gives before being asked. Below this is one who gives after being asked. Below this is one who gives less than what is appropriate but gives it happily. Below this is one who gives unhappily. [AJWS translation]