Chapter: "Those who take an oath, not to have sexual relations with their wives, must wait four months."

Allah's Messenger (ﷺ) took an oath that he would abstain from his wives, and at that time his leg had been sprained (dislocated). So he stayed in the Mashruba (an attic room) of his for 29 days. Then he came down, and they (the people) said, "O Allah's Messenger (ﷺ)! You took an oath to abstain from your wives for one month." He said, "The month is of twenty nine days."

Ibn `Umar used to say about the Ila (which Allah defined (in the Holy Book), "If the period of Ila expires, then the husband has either to retain his wife in a handsome manner or to divorce her as Allah has ordered."