Is it permissible to wear sandals (Na'l)?
Chapter on What the Muhrim Must Avoid and What is Permissible for Him
Al-Mughni
Book of Hajj
Primary text
Wearing sandals, in any condition, is permissible. It is not obligatory to remove any part of the sandal because the permissibility was stated without restriction. This ruling is supported by the analogy that if cutting the two leather coverings (khuffayn) that cover the feet and legs is not obligatory, then cutting the strap of the sandal is even less obligatory. Furthermore, the straps are customary parts of the sandal, and customary items are not required to be removed, similar to other straps on the sandal. Finally, removing the strap (qayd) and the heel strap (aqab) might make walking in the sandals impossible due to the sandals falling apart, thus removal is not obligatory, similar to the toe cover (qibal).
Supporting text
There is a narration from Ahmad stating that one must pay compensation (iftida') for the strap (qayd) on the sandal because such sandals are not known to be made in that manner. Furthermore, when one enters the state of Ihram, the support structure on the sandals and the heel strap should be removed, as Ata' stated that this incurs a penalty (dam). Ibn Abi Musa, in Al-Irshad, stated that compensation is due for the strap and the heel strap, where the strap is defined as the transverse leather strip on the instep.