Bukhari :: Book 3 :: Volume 31 :: Hadith 135
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."
Source materials are from the University of Southern California MSA site|
Hadith eBooks converted from Imaan Star