Musnad Ahmad Hadith 23794

It is narrated from Abu Tufail (may Allah be pleased with him) (mentioning the construction of the Ka'bah during the time of ignorance) that when the construction of the House of Allah began (the Quraysh first completely demolished it and started rebuilding it with stones from the valley), people were carrying stones, among whom was also the Noble Prophet (ﷺ). (The Quraysh had kept it twenty cubits long.) The Noble Prophet (ﷺ) was wearing a woolen sheet, but during the carrying of stones, it became difficult to manage it, so the Noble Prophet (ﷺ) placed that sheet on his shoulder. At that moment, someone called out, "Cover your private part," so the Noble Prophet (ﷺ) threw down the stone and wrapped himself in his sheet. Peace and blessings be upon him.