والظرف متعلق بجملة عند الأكثر، وهي استقرّ مثلاً: تقول: زيد في الدار، تقديره: زيد استقرّ في الدار.
Translation: According to the view described by the author, the locative expression is attached to an understood clause such as «اسْتَقَرَّ» (“settled/remained”).
The verb is not overt in «زَيْدٌ فِي الدَّارِ». The reconstruction «زَيْدٌ اسْتَقَرَّ فِي الدَّارِ» explains the understood relation; it is not a claim that an extra verb appears in the actual sentence.