[A Wife’s Stipulation That the Husband Not Remove Her from Her Town]

Answer—and Allah grants success: He is not permitted to remove her from that town; rather, he is obliged to fulfill what he committed himself to, by His saying: “O you who have believed, fulfill [all] contracts.” [al-Mā’idah:1]. And likewise the other verses that command fulfilling covenants and compacts; and in the ḥadīth: “The signs of a hypocrite are three: when he speaks, he lies; when he promises, he breaks his promise; and when he is entrusted, he betrays the trust.”
Allah praised His Prophet Ismāʿīl, peace be upon him, in His saying: “And mention in the Book, Ishmael. Indeed, he was true to his promise, and he was a messenger and a prophet. And he used to enjoin on his people prayer and zakāh and was to his Lord pleasing.” [Maryam: 54–55]. In this verse Allah praised Ismāʿīl with several praises, the first of which is truthfulness in promise—and for a reason Allah made that the first attribute mentioned.
Yes: the statement of the scholars of the madhhab—“the contract is valid and the condition is void”—means that failure to fulfill such a condition does not invalidate the contract; thus, if a man fails to honor a condition he undertook, that failure does not affect the marriage contract itself, since it is not among the obligations entailed by the contract.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.1