Narrated to me Harun ibn 'Abdullah: Hajjaj ibn Muhammad narrated to us, saying: Ibn Jurayj said: Yahya ibn 'Abdullah ibn Muhammad ibn Sayfi informed me that 'Ikrimah ibn 'Abd al-Rahman ibn al-Harith informed him that Umm Salamah — may Allah be pleased with her — informed him that the Prophet, peace and blessings be upon him, swore that he would not enter upon some of his wives for a month. When twenty-nine days had passed, he went to them in the morning — or in the evening — and it was said to him: "O Prophet of Allah, you swore that you would not enter upon us for a month." He said: "Indeed, the month may be twenty-nine days."