The mother said: “he won't know what we did."
The daughter said, "Such an income would not be lawful; as a Muslim I would not do anything whereby other Muslims are deceived."
The mother said, "But there is neither the Khalifa nor any of his officers here to see what we do. Daughter, go to bed now and tomorrow I will myself mix the milk with water for you."
Thereupon the mother remained quiet. The lamp was extinguished and the mother and the daughter went to sleep.
Having heard all of this, Khalifa Umar knew of the mother's plan. The next day, Khalifa Umar sent a man to buy milk from the woman. To his surprise, the milk didn't have any water added to it. The daughter knew right from wrong and was strong enough to hold her ground with her mother.
Khalifa Umar said to his friend, "The daughter stayed strong even when her mother wanted her to do something wrong. She deserves a reward. What reward should I give her?"
"She should be rewarded with some money," said lbn Abbas.
Khalifa Umar said, "A daughter like her would be a great wife for my son. Someday she would make a good mother, honest, and a great role-model. Because she is so good, she should be given the greatest gift in the nation, because everyone in the nation should learn how to be good like her."
The Khalifa sent for the young woman and her mother to come to his court. The mother shivered because she was afraid when she stood before the mighty ruler, but the young woman stood boldly and without fear.
Then, in front of everyone, Khalifa Umar told how he had overheard the mother and daughter talking about adding water to the milk, and how the daughter had done what was right, even when her mother told her not to.
Someone said that the mother should be punished, but the Khalifa said that usually he would, but he had forgiven her because her daughter was so good. Then he turned to the daughter and said, "Islam needs daughters like you and as a Khalifa of Islam, it is my job to reward you. I would like to reward you by having you as my daughter."
Then the Khalifa called his sons and said to them, "Here is a wonderful young woman who would make a great wife and mother. I don't know a better bride than this girl who is so good." Abdullah and Abdur Rahman, the oldest sons of the Khalifa, were already married. Asim, the third son wasn't married yet, and he offered to marry the young woman. When the young woman and her mother agreed, Asim married her and the milkmaid became the daughter-in-law of the Khalifa. From this union was born a daughter, Layla, who became in due course the mother of Omar bin Abdul Aziz, who became one of the most great and unique Khalifas.