Mishkat al-Masabih 13 Marriage كتاب النكاح 63

وَعَنْ عُقْبَةَ بْنِ عَامِرٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَحَقُّ الشُّرُوطِ أَنْ تُوفُوا بِهِ مَا اسْتَحْلَلْتُمْ بِهِ الْفروج»

‘Uqba b. ‘Amir reported God’s Messenger as saying, “The most worthy conditions you fulfil are those by which you make sexual intercourse lawful.” (Bukhari and Muslim.)