Musnad Ahmad 1153:2289

Ya'qub narrated to us, he said: My father narrated to us, from Ibn Ishaq, he said: Hisham ibn 'Urwah narrated to me, from his father, from 'Aishah, the wife of the Prophet, may Allah bless him and grant him peace, she said: Khuwaylah bint Hakim ibn Umayyah ibn Harithah ibn al-Awqas al-Sulamiyyah entered upon me, and she was married to 'Uthman ibn Maz'un. She said: The Messenger of Allah, may Allah bless him and grant him peace, saw the disheveled state of her appearance, so he said to me: "O 'Aishah, how disheveled is the appearance of Khuwaylah?" She said: I said: O Messenger of Allah, she is a woman who has no husband; she fasts the day and stands in prayer the night, so she is like one who has no husband, and she has neglected herself and let herself go. She said: So the Messenger of Allah, may Allah bless him and grant him peace, sent for 'Uthman ibn Maz'un, and he came to him. He said: "O 'Uthman, do you turn away from my Sunnah?" He said: He said: No, by Allah, O Messenger of Allah, but it is your Sunnah that I seek. He said: "For I sleep and I pray, and I fast and I break my fast, and I marry women. So fear Allah, O 'Uthman, for your family has a right upon you, and your guest has a right upon you, and your self has a right upon you. So fast and break your fast, and pray and sleep."