While Messenger of Allah ﷺ was carrying stones (along) with the people of Mecca for (the building of) the Kaʿba wearing an Izar (waist-sheet cover), his uncle Al-ʿAbbas said to him, "O my nephew! (It would be better) if you take off your Izar and put it over your shoulders underneath the stones." So he took off his Izar and put it over his shoulders, but he fell unconscious and since then he had never been seen naked. (Using translation from Bukhārī 364)
أَنَّ رَسُولَ اللهِ ﷺ كَانَ يَنْقُلُ مَعَهُمْ حِجَارَةَ الْكَعْبَةِ وَعَلَيْهِ إِزَارٌ فَقَالَ لَهُ الْعَبَّاسُ عَمُّهُ يَا ابْنَ أَخِي لَوْ حَلَلْتَ إِزَارَكَ فَجَعَلْتَهُ عَلَى مَنْكِبَيْكَ دُونَ الْحِجَارَةِ قَالَ فَحَلَّهُ فَجَعَلَهُ عَلَى مَنْكِبَيْهِ فَسَقَطَ مَغْشِيًّا عَلَيْهِ فَمَا رُئِيَ بَعْدَ ذَلِكَ الْيَوْمِ عُرْيَانًا