Hadith: If it is wide, cross its ends; and if it is tight, pull it around your waist

عن سعيد بن الحارث قال: سَأَلنَا جابر بن عبد الله عن الصلاة في الثوب الواحد؟ فقال: خَرَجْت مع النبي صلى الله عليه وسلم في بعض أَسْفَارِهِ، فَجِئْت لَيْلَةً لِبَعْض أَمْرِي، فَوَجَدْتُهُ يُصَلِّي، وعليَّ ثوب واحد، فَاشْتَمَلْتُ به وَصَلَّيْتُ إلى جَانِبِه، فلما انْصَرف قال: «ما السُّرَى يا جابر»؟ فأخْبَرتُه بحاجتي، فلما فَرَغْتُ قال: «ما هذا الِاشْتِمَال الذي رَأيْتُ»؟ قلت: كان ثوب -يعني ضاق-، قال: «فإن كان واسعا فَالتَحِفْ به، وإن كان ضَيِّقًا فَاتَّزِرْ به». ولمسلم: «إذا كان واسِعًا فخَالف بين طَرَفَيْه، وإذا كان ضَيِّقًا فَاشْدُدْه عَلَى حَقْوِكَ».
[صحيح] - [متفق عليه]

Sa‘īd ibn al-Hārith reported: We asked Jābir ibn ‘Abdullāh about praying in one garment and he said: 'I traveled with the Prophet (may Allah's peace and blessings be upon him) on one of his journeys, and I came one night for something I needed and found him praying. I had one garment on me, so I wrapped it around myself and prayed by his side. When he finished, he said: "O Jābir, what has brought you here at night?" I told him of my need. When I finished, he said: "O Jābir, what is this wrapping up that I have seen?" I said: "It is a (tight) garment." He said: "If it is large enough, cover yourself with it; and if it is tight, use it as a waist sheet." The version narrated by Muslim reads: "If it is wide, cross its ends; and if it is tight, pull it around your waist."
[Authentic hadith] - [Narrated by Bukhari & Muslim]

Explanation

Jābir (may Allah be pleased with him) went with the Prophet (may Allah's peace and blessings be upon him) on one of his journeys. One night he wanted something from the Prophet so he went to tell him about it and found him praying. Jābir was wearing only one item of clothing, so he wrapped himself with it and placed it ends on his shoulders, and prayed next to the Prophet. When the Prophet finished praying, he inquired about the reason Jābir was out at this late hour. Jābir told him what he came for, and when he was done, the Prophet (may Allah's peace and blessings be upon him) expressed his disapproval of his wrapping himself with his garment because it was tight, and gave him the following order: if the garment is wide then he should wrap his upper and lower body with it, placing it upon his shoulders with the left end on the right shoulder and vice versa, such that it would be an over garment (Ridā) as well as a waist sheet (Izār), covering his entire body. This is more efficient in covering the ‘Awrah and better looking. If the garment is tight and cannot serve as both an over garment and a waist sheet, then he should wear it as a waist sheet only by tightening it around his waist, thereby covering the lower half of his body.