Chapter 83: Oaths and Vows
Narrated Anas: Allah' s Messenger (ﷺ) took an oath for abstention from his wives (for one month), and during those days he
had a sprain in his foot. He stayed in a Mashrubah (an upper room) for twenty-nine nights and then
came down. Then the people said, "O Allah' s Messenger (ﷺ)! You took an oath for abstention (from your
wives) for one month." On that he said, "A (lunar) month can be of twenty-nine days."
Sahih al-Bukhari 6684