إِذَا أُحْصِرَ الْمُحْرِمُ بِعَدُوٍّ، أَوْ أَصَابَهُ مَرَضٌ مَنَعَهُ مِنَ الْمُضِيِّ: حَلَّ لَهُ التَّحَلُّلُ.
Translation: If a person in ihram is obstructed by an enemy, or illness prevents continuing, release from ihram becomes permissible.
The passive uhsira means was restrained; manaʿahu min al-mudiyy means it prevented going onward. The impediment, not illness as a label alone, is decisive.
The clause permits release; it does not say ihram ends automatically. The required procedure follows.