Moreover, if a marriage is held to be valid and binding, this must mean either that it remains so together with the unlawful, invalid stipulation—which contradicts the textual evidence and consensus—or that it remains so while the stipulation is annulled. The latter would bind the contracting party to a contract to which he did not consent and which Allah did not impose upon him.

It is well known that the obligations arising from a contract become binding either because the Lawgiver imposes them or because the contracting party undertakes them. The first category includes contracts that the Lawgiver requires a person to enter into, just as He requires a non-Muslim in a state of war to embrace Islam, and requires someone who has broken a binding oath to make one expiation through manumission and fasting; and just as He requires someone who needs something else … (1) to buy and sell in various circumstances. The “second” is reciprocal exchange … (2), just as a guarantor becomes liable for the debtor’s debt while the debtor remains liable for it, and just as each party to a sale, settlement or lease becomes bound by what he undertakes towards the other.

That being so, when a marriage contains an invalid stipulation, the Lawgiver has not required the person concerned to enter into it without that stipulation, nor has he himself undertaken to enter into it without the stipulation. Binding him to something that he neither undertook himself nor was required to undertake by the Lawgiver amounts to imposing upon people obligations that neither Allah nor His Messenger imposed upon them. This is impermissible.

Furthermore, stipulations in marriage are more binding than those in sales, as demonstrated by his statement in the authentic hadith:

“The stipulations most deserving of fulfilment are those by which you have made marital intimacy lawful.”

Now, a sale is permissible only by mutual consent, for Allah Most High says:

“Unless it is trade by mutual consent among you.”

Thus, marriage has an even stronger claim to require mutual consent. The contracting party consented to the invalid contract only on those particular terms.