After his conversion to Islam, Uthman was married by the Holy Prophet to his second daughter Ruqayya. Uthman migrated with Ruqayya to Abyssinia. He returned from Abyssinia and then migrated with his wife to Yathrib in 622. In Yathrib renamed Madina, Uthman carried on his business as a merchant. His business flourished, and Uthman and Ruqayya lived on happily for sometime in Madina. Such happiness was however short-lived. In 624 C.E. Ruqayya fell ill and died when the Holy Prophet and the Muslims were fighting with the Quraish at the battlefield of Badr. The news of the Muslim victory of Badr was received at Madina when the good lady was being buried. The Holy Prophet could not attend the funeral of Ruqayya.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari