Narrated ‘Aisha:
Allah’s Apostle said, “When a woman gives in charity some of the foodstuff (which she has in her house) without spoiling it, she will receive the reward for what she has spent, and her husband will receive the reward because of his earning, and the storekeeper will also have a reward similar to it. The reward of one will not decrease the reward of the others . ”
Sahih Bukhari, Volume 2, Book24, Number 506