To tie Izar (dress worn below the waist) at one's back while offering Salat (prayers)

Sahih al-Bukhari · Book 8 · Hadith 352

حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، قَالَ حَدَّثَنَا عَاصِمُ بْنُ مُحَمَّدٍ، قَالَ حَدَّثَنِي وَاقِدُ بْنُ مُحَمَّدٍ، عَنْ مُحَمَّدِ بْنِ الْمُنْكَدِرِ، قَالَ صَلَّى جَابِرٌ فِي إِزَارٍ قَدْ عَقَدَهُ مِنْ قِبَلِ قَفَاهُ، وَثِيَابُهُ مَوْضُوعَةٌ عَلَى الْمِشْجَبِ قَالَ لَهُ قَائِلٌ تُصَلِّي فِي إِزَارٍ وَاحِدٍ فَقَالَ إِنَّمَا صَنَعْتُ ذَلِكَ لِيَرَانِي أَحْمَق…

Narrated Muhammad bin Al-Munkadir: Once Jabir prayed with his Izar tied to his back while his clothes were Lying beside him on a wooden peg. Somebody asked him, "Do you offer your prayer in a single Izar?" He replied, "…

Sahih al-Bukhari · Book 8 · Hadith 353

حَدَّثَنَا مُطَرِّفٌ أَبُو مُصْعَبٍ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ أَبِي الْمَوَالِي، عَنْ مُحَمَّدِ بْنِ الْمُنْكَدِرِ، قَالَ رَأَيْتُ جَابِرَ بْنَ عَبْدِ اللَّهِ يُصَلِّي فِي ثَوْبٍ وَاحِدٍ وَقَالَ رَأَيْتُ النَّبِيَّ صلى الله عليه وسلم يُصَلِّي فِي ثَوْبٍ‏.‏

Narrated Muhammad bin Al Munkadir: I saw Jabir bin `Abdullah praying in a single garment and he said that he had seen the Prophet (ﷺ) praying in a single garment.