Marvelous Stories from Quran
"There once was a girl named 'Umm Ammar" who sells the milk of a she-camel. Her mother kept on telling her to add water to the milk so that they would have a greater quantity of milk. The daughter told her mother that although they did that prior to becoming Muslims, now that they were believers, they could no longer practice deceitful business dealings. "Everything we say and do is witnessed by Allah, if not witnessed by Khalifa Omar," she said.
Khalifa Omar ibn al-Khattab overheard the mother and daughter talking about adding water to the milk. He was surprised how the daughter had done what was right, against her mother's will. He called his third son Asim, and said, ""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.""