كتاب النكاح
Read the English translation first, with the original Arabic directly underneath.
Narrated 'Alqamah:
It was narrated that 'Alqamah said: "I was with Ibn Mas'ud while he was with 'Uthman, may Allah be pleased with him, and 'Uthman said: 'The Messenger of Allah came out to some fityah (young men)--Abu 'AbdurRahman said, 'I did not understand (the word) fityah as I would want'-- and said: 'Whoever among you can afford it, let him get married, for it is more effective in lowering the gaze and guarding chastity, and whoever cannot, then fasting will be a restraint (wija') for him.'"
مَنْ كَانَ مِنْكُمْ ذَا طَوْلٍ فَلْيَتَزَوَّجْ فَإِنَّهُ أَغَضُّ لِلْبَصَرِ وَأَحْصَنُ لِلْفَرْجِ وَمَنْ لاَ فَالصَّوْمُ لَهُ وِجَاءٌ