Obligatory Charity Tax (Zakat)

Bukhari :: Book 2 :: Volume 24 :: Hadith 512

Narrated Abu Burda bin Abu Musa:

that his father said, "Whenever a beggar came to Allah's Apostle or he was asked for something, he used to say (to his companions), "Help and recommend him and you will receive the reward for it; and Allah will bring about what He will through His Prophet's tongue."