I cannot obey Allah in public and disobey Him in private
Narrated `Abdullah ibn Zayd ibn Aslam, from his father, from his grandfather, who said:
When I was accompanying `Umar ibn al-Khattab (radi Allahu ‘anhu) on his patrol of Madinah at night, he felt tired, so he leant against a wall. It was the middle of the night, and (we heard) a woman say to her daughter, “O my daughter, get up and mix that milk with some water.” The girl said, “O Mother, did you not hear the decree of Amir al-Mu’minin today?” The mother said, “What was that?” The girl said, “He ordered someone to announce in a loud voice that milk should not be mixed with water.” The mother said, “Get up and mix the milk with water; you are in a place where `Umar cannot see you.” The girl told her mother, “I cannot obey Him (Allah) in public and disobey Him in private.”
`Umar (radi Allahu ‘anhu) heard this, and told me: “O Aslam, go to that place and see who that girl is, and to whom she was speaking, and whether she has a husband.” So I went to that place, and I saw that she was unmarried, the other woman was her mother, and neither of them had a husband. I came to `Umar (radi Allahu ‘anhu) and told him what I had found out. He called his sons together, and said to them: “Do any of you need a wife, so I can arrange the marriage for you? If I had the desire to get married, I would have been the first one to marry this young woman.” `Abdullah said: “I have a wife.” `Abd al-Rahman said: “I have a wife.” `Asim said: “I do not have a wife, so let me marry her.” So `Umar arranged for her to be married to `Asim. She gave him a daughter, who grew up to be the mother of `Umar ibn `Abd al-`Aziz (rahimahullah).
[Related in Sifat al-Safwah and Wafiyat al-A'yan and cited by Ibn al-Jawzi in Ahkam al-Nisa' pp. 441, 442]