The grandfather of Abu ‘Abdullah Bin Zayd Bin Aslam narrated an interesting incident during the rule of Umar Bin Al-Khattab (may Allah be pleased with him):
Once when I was accompanying Umar Bin Al-Khattab (may Allah be pleased with him) on his patrol of Madina at night, it so happened that he leaned against a wall (to rest) when he felt tired. It was midnight, 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 (chief of the believers) 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 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 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.” Abdur-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. The woman gave birth to a daughter, who grew up to be the mother of Umar Bin Abdul Aziz.
(Sifat Al-Safwah, Wafiyat Al-A’yan and cited by Ibn Al-Jawzi in Ahkam Al-Nisa’ pg. 441, 442)
Note: Umar Bin Abdul Aziz is the one of the most respected caliphs for his honesty, justice and devoutness, after the four rightly-guided caliphs.