English Translation
Narrated Anas: Allah's Apostle vowed to keep aloof from his wives for one month, and he had dislocation of his leg. So, he stayed in a Mashruba for 29 nights and then came down. Some people said, "O Allah's Apostle! You vowed to stay aloof for one month," He replied, "The month is of 29 days."
This hadith is from Sahih al-Bukhari, the most rigorously authenticated collection in Islamic scholarship. No editorial opinion is added.