Chapter on Stipulations and Defects in Marriage
If, at the time of the contract, the woman stipulates that her co-wife be divorced, that the husband will not take a concubine1, that he will not marry another wife, that he will not remove her from her house or her town, or she requires a specified cash payment or an increase to her dowry, the stipulation is valid; should he violate it, she may annul the marriage.

If one guardian marries off his ward to a man on the condition that the latter will, in return, marry him his own ward, and the two guardians execute this exchange without naming a dowry, both marriages are void. If a dowry is specified for each woman, the two marriages are valid.

Should a man marry a woman on the condition that once he has made her lawful for her first husband he will divorce her (tahlīl), or he merely intends that without stating it, or he says, “I marry you when the first of the month arrives,” or “if her mother consents,” or “when tomorrow comes I will divorce her,” or he limits the marriage to a fixed term2, every one of these arrangements is invalid.

Section
If he stipulates that she is to have no dowry, or no maintenance, or that he will allot her fewer—or more—nights than her co-wife, or he inserts an option clause, or he makes the marriage contingent on the dowry being produced by a certain time, otherwise there is to be no marriage