The Prophet ﷺ forbade wrapping oneself in the Samma manner, and forbade a man from sitting with his knees drawn up in a single garment with nothing covering his private parts.
حدثنا حجاج عن ابن جريج قال أخبرني ابن شهاب عن عبيد الله بن عبد الله
أن النبي ﷺ نهى عن اشتمال الصماء وأن يحتبي الرجل في ثوب واحد ليس على فرجه منه شيء
Its isnad is sahih, its narrators are imams. Hajjaj is Ibn Muhammad, Ibn Jurayj is Abdul-Malik bin Abdul-Aziz, and Ibn Shihab is Zuhri, Muhammad bin Muslim bin Abdullah. The hadith has already appeared at 10695. Sahih.