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).
Sahih al-Bukhari Book 67, Hadith 86
← Previous Hadith The Prophet (ﷺ) said to a man, "Marry, even with (a Mahr equal to) an iron ring."

Sahih al-Bukhari Book 67, Hadith 85 Next Hadith → The Prophet (ﷺ) said, "It is not lawful for a woman (at the time of wedding) to ask for the divorce of her sister (i.e. the other wife of her would-be husband) in order to have everything for herself, for she will take only what has been written for her."

Sahih al-Bukhari Book 67, Hadith 87