Obligatory Charity Tax (Zakat)
Bukhari :: Book 2 :: Volume 24 :: Hadith 518
Narrated 'Aisha:
Allah's Apostle said, "When a woman gives in charity from her husband's meals without wasting the property of her husband, she will get a reward for it, and her husband too will get a reward for what he earned and the store-keeper will have the reward likewise."