He was most generous and for his generosity he was called Uthman, the Ghani. He helped his relatives liberally. He was very particular in helping the orphans and the widows He allowed them liberal stipends. On the occasion of the expedition to Tabuk, the Holy Prophet invited contributions from his followers. Uthman made the greatest contribution. The Holy Prophet gave Uthman the tidings of paradise for his unbounded generosity.
"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