Hadith 4:42
Ibn al-Mubarak narrated to us, from Musa ibn Ubaydah, from Jumhan, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "For everything there is a zakat (purification), and the zakat of the body is fasting."
حدثنا بن مبارك عن موسى بن عبيدة عن جمهان عن أبي هريرة قال قال رسول الله صلى الله عليه وسلم لكل شيء زكاة وزكاة البدن الصوم