«أيما امرأة نكحت نفسها بغير إذن وليها فنكاحها باطل»
A woman who contracts marriage without her guardian's permission has, in the wording of this report, an invalid marriage.
The text contrasts this with «فَلَا تَعْضُلُوهُنَّ أَنْ يَنْكِحْنَ أَزْوَاجَهُنَّ», which prohibits obstructing women from marrying their spouses. Jurists differ about how these texts bear on the woman's contracting capacity and the guardian's role.
The Hanafi analysis emphasizes the Qur'anic attribution of marrying to women; other schools combine and prioritize the proofs differently. This is an interpretive disagreement about evidence, not rejection of either source of law.