Imam Shafi'i (may Allah have mercy on him) narrates that once a woman came to Hazrat Umar (may Allah be pleased with him) and said, "Ameer al-Mu'minin! There is probably no one in the world as righteous as my husband. He fasts all day and prays all night." Saying this, she became silent. Hazrat Umar (may Allah be pleased with him) did not fully understand the meaning of her words and said, "May Allah bless you and forgive you. Righteous women praise their husbands in this way."
The woman heard this sentence, hesitated for a while, stopped, and then stood up to leave.
Ka'b bin Sawar (may Allah be pleased with him) was also present. When he saw the woman leaving, he said to Hazrat Umar (may Allah be pleased with him), "Ameer al-Mu'minin! You did not understand her words, she did not come to praise her husband but to complain. Her husband, in his zeal for worship, does not fulfill the full rights of marriage."
Hazrat Umar (may Allah be pleased with him) said, "Oh, that's the matter. Call her." The woman came back and upon inquiry, it was found that Hazrat Ka'b bin Sawar's (may Allah be pleased with him) assumption was correct. Hazrat Umar said to him, "Now you decide on this."
Hazrat Ka'b said, "Ameer al-Mu'minin! How can I decide in your presence??"
Hazrat Umar said, "Yes! You understood her complaint, you should resolve it."
Upon this, Hazrat Ka'b said, "Ameer al-Mu'minin, Allah Almighty has allowed a man to marry a maximum of four women. Even if a person acts on this permission and marries four wives, each wife gets one day and night out of four. From this, it is known that every fourth day and night is the right of one wife. Therefore, you should decide that this woman's husband can worship for three days, but he must spend the fourth day with his wife."
Hearing this decision, Hazrat Umar was overjoyed and said, "This decision is even more amazing than your initial understanding and wisdom."
After this, Hazrat Umar appointed Hazrat Ka'b as the Qazi of the city of Basra.