Charity is due from every Muslim

'Ala kulli muslimin sadaqah. Fa-qalu: ya Nabiyya-llah, fa-man lam yajid? Qal: ya'malu bi-yadihi fa-yanfa'u nafsahu wa yatasaddaq. Qalu: fa-in lam yajid? Qal: yu'inu dha-l-hajati-l-malhuf. Qalu: fa-in lam yajid? Qal: fal-ya'mal bi-l-ma'ruf, wal-yumsik 'ani-sh-sharr, fa-innaha lahu sadaqah.

"Every Muslim has to give charity. They asked: O Prophet of Allah, what of someone who has nothing? He said: He works with his hands, benefits himself and gives charity. They asked: And if he cannot? He said: He helps someone in need who calls for help. They asked: And if he cannot? He said: Then let him do good and hold back from evil, for that is charity for him."

Narrated by Abu Musa al-Ash'ari. Sahih al-Bukhari 1445, Sahih Muslim 1008