question #3 Sahih Muslim 1111c, Book 13, Hadith 103 : How does feeding the poor serve as a form of expiation in Islamic teachings?

Can you find a slave (to grant him freedom)? He said: No. He (the Prophet again) said: Can you afford to observe fasts for two (consecutive) months? He said: No. He (the Holy Prophet) said: Then feed sixty poor men.