صحيح ابن خزيمه
Sahih Ibn Khuzaymah
جماع أبواب الصلاة على البسطChapters on Praying on Mats
(418) بَابُ الصَّلَاةِ فِي النَّعْلَيْنِ418 Chapter: Praying in Sandals.
Hadith Q1009
وَالْخِيَارِ لِلْمُصَلِّي بَيْنَ الصَّلَاةِ فِيهِمَا وَبَيْنَ خَلْعِهِمَا وَوَضْعِهِمَا بَيْنَ رِجْلَيْهِ، كَيْ لَا يُؤْذِيَ بِهِمَا غَيْرَهُ
The worshipper has the option to pray while wearing shoes or to take them off and place them between his feet, so that they do not cause harm to other worshippers.
