[Machine] The Prophet ﷺ never took off his shoes in prayer except for once. When he removed them, the people followed his example. He then asked, "Why did you do that?" They replied, "You took off your shoes, so we did too." The Prophet ﷺ said, "Indeed, Gabriel informed me that there was some impurity or harm in them."  

أَنَّ النَّبِيَّ ﷺ لَمْ يَخْلَعْ نَعْلَيْهِ فِي الصَّلَاةِ قَطُّ إِلَّا مَرَّةً وَاحِدَةً خَلَعَ فَخَلَعَ النَّاسُ فَقَالَ «مَا لُكُمْ» قَالُوا خَلَعْتَ فَخَلَعْنَا فَقَالَ «إِنَّ جِبْرِيلَ أَخْبَرَنِي أَنَّ فِيهِمَا قَذَرًا أَوْ أَذًى»  

[Machine] The Prophet Muhammad صلى الله عليه وسلم prayed with us, and after he finished praying, he took off his sandals and placed them on his left side. The people also took off their sandals. When he finished his prayer, he asked, "Why did you take off your sandals?" They replied, "We saw you take off yours, so we took off ours." He said, "I did not take them off due to any discomfort, but the angel Gabriel informed me that there was some impurity on them. So, when one of you enters the mosque, let him check his sandals. If there is any impurity on them, he should wipe it off."  

صَلَّى بِنَا رَسُولُ اللَّهِ ﷺ فَلَمَّا صَلَّى خَلَعَ نَعْلَيْهِ فَوَضَعَهُمَا عَنْ يَسَارِهِ فَخَلَعَ الْقَوْمُ نِعَالَهُمْ فَلَمَّا قَضَى صَلَاتَهُ قَالَ «مَا لَكُمْ خَلَعْتُمْ نِعَالَكُمْ؟ » قَالُوا رَأَيْنَاكَ خَلَعْتَ فَخَلَعْنَا قَالَ «إِنِّي لَمْ أَخْلَعْهُمَا مِنْ بَأْسٍ وَلَكِنَّ جِبْرِيلَ أَخْبَرَنِي أَنَّ فِيهِمَا قَذَرًا فَإِذَا أَتَى أَحَدُكُمُ الْمَسْجِدَ فَلْيَنْظُرْ فِي نَعْلَيْهِ فَإِنْ كَانَ فِيهِمَا أَذًى فَلْيَمْسَحْهُ»  

"إِنَّ النَّبِىَّ ﷺ بَيْنَا هَو يُصَلِّى يَوْمًا خَلَعَ نَعْلَيْهِ، فَخَلَعَ النَّاسُ نِعَالَهُمْ، فَلَّما انْصَرَفَ قَالَ: مَا شَأنُكُمْ؟ خَلَعْتُمْ نِعَالَكُمْ؟ قَالُوا: رَأَيْنَاكَ خَلَعْتَ فَخَلَعْنَا، فَقَالَ: إِنَّ جِبْريلَ أَتَانِى فَأَخْبَرنِى أَنَّ بِهمَا قَذَرًا، فَإِذَا جَاءَ أَحَدُكُمْ الْمسْجِدَ فَليَنْظرْ نَعْلَيْهِ، فإِنْ كَانَ بِهِمَا قَذَرٌ فَليُدلّكهُمَا بِالأَرْضِ".