Abd al-Rahman bin Yazid (may Allah have mercy on him) narrates that Sayyiduna Abdullah (may Allah be pleased with him) said: We were with the Messenger of Allah (peace and blessings be upon him) as young men and we had nothing, so he said: "O young men! Whoever among you is able to marry, let him marry, for it lowers the gaze and guards the private parts. And whoever is not able, let him hold to fasting, for fasting will be a shield for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8453