I heard Sa'd (b. Abi Waqqas) saying that the idea of 'Uthman b. Maz'un for living in celibacy was rejected (by the Holy Prophet), and if he had been given permission they would have got themselves castrated.
سَمِعْتُ سَعْدًا يَقُولُ رُدَّ عَلَى عُثْمَانَ بْنِ مَظْعُونٍ التَّبَتُّلُ وَلَوْ أُذِنَ لَهُ لاَخْتَصَيْنَا