(42) باب الشُّرُوطِ فِي النِّكَاحِ .
It was narrated from 'Utbah bin 'Amir that the Messenger of Allah said:
"The conditions that are most deserving of fulfillment, are those by means of which the private parts become allowed to you."
Reference: Sunan an-Nasa'i 3281
In-book reference: Book 26, Hadith 86
English translation: Vol. 4, Book 26, Hadith 3283