Sahih Muslim Book 008, Hadith Number 3231.

Chapter: One who can support a wife should marry.

'Alqama reported: While I was walking with 'Abdullah at Mina, 'Uthman happened to meet him. He stopped there and began to talk with him. Uthman said to him: Abu 'Abd al-Rahman, should we not marry you to a young girl who may recall to you some of the past of your bygone days; thereupon he said: If you say so, Allah's Messenger (May peace be upon him) said: O young men, those among you who can support a wife should marry, for it restrains eyes from casting (evil glances) and preserves one from immorality; but those who cannot should devote themselves to fasting for it is a means of controlling sexual desire.