The conqueror of Persia, Sayyiduna Sa’d bin Abi Waqqas (may Allah be pleased with him), used to say: The Noble Prophet (peace and blessings be upon him) forbade ‘Uthman bin Maz’un (may Allah be pleased with him) from abstaining from marriage; if he had permitted him, we would have become eunuchs.
Narrated Abu Huraira (may Allah be pleased with him): I said to the Messenger of Allah (peace and blessings be upon him), "I am a young man and I fear that I may commit adultery, and I do not have the means to marry." But the Messenger of Allah (peace and blessings be upon him) did not reply to me. I repeated my request in the same manner, but he remained silent. I asked again, but he did not answer. When I repeated it once more, the Messenger of Allah (peace and blessings be upon him) replied: "Abu Huraira! The pen has dried (after writing) what is decreed for you (your destiny is already written and cannot be changed), whether you become castrated or not."