It is narrated from Sayyiduna Ibn Mas’ud (may Allah be pleased with him) that we used to participate in battles with the Prophet (peace and blessings be upon him), and there were no women with us. Once we said: O Messenger of Allah! Should we not get ourselves castrated? The Prophet (peace and blessings be upon him) forbade us from doing so. Then he recited this verse: «﴿يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تُحَرِّمُوا طَيِّبَاتِ مَا أَحَلَّ اللّٰهُ لَكُمْ . . .﴾» [المائدة: 87] "O you who believe! Do not make unlawful the good things which Allah has made lawful for you."