The Prophet ﷺ said: "The stipulations most entitled to be abided by are those with which you are given the right to enjoy the (women's) private parts (i.e. the stipulations of the marriage contract).
عَنِ النَّبِيِّ ﷺ قَالَ أَحَقُّ مَا أَوْفَيْتُمْ مِنَ الشُّرُوطِ أَنْ تُوفُوا بِهِ مَا اسْتَحْلَلْتُمْ بِهِ الْفُرُوجَ