Halakha Mazmur 112:5: Mishneh Torah, Gifts to the Poor

If a poor person comes and asks for what is sufficient to fill his needs and one does not have the means to provide it for him, one gives according to his means. How much is this? One-fifth of one's assets is the best possible way, but one-tenth is the usual way. Less than this is a bad sign, and never should one restrain himself from a third of a shekel a year. Anyone who has not given at least this much has not fulfilled the mitzvah.¹³²See Babylonian Talmud Bava Batra 9a. Even a poor person who lives on tzedakah is obligated to give tzedakah to another.¹³³See Babylonian Talmud Gittin 7b.