Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) took an oath of abstention (ila’) from his wives, and at that time, he also had an injury on his leg. The Prophet (peace and blessings be upon him) stayed in an upper room for twenty-nine days, then he came down from there. The people said: O Messenger of Allah (peace and blessings be upon him)! You had taken an oath of abstention for one month. The Prophet (peace and blessings be upon him) said: A month can (sometimes) be of twenty-nine days.