The Prophet ﷺ forbade two ways of wearing garments, the Samma, and that a man wraps himself in his garment while sitting with his knees drawn up, leaving his private parts uncovered.
أن النبي ﷺ نهى عن لبستين: الصماء وأن يحتبي الرجل بثوبه ليس على فرجه منه شيء.
Tirmidhi (1758) and Abu Dawud (4080) both narrated it from the hadith of Abu Salih, from Abu Hurairah, who related it, and the wording given is that of Tirmidhi. Its isnad is sahih.As for his saying, "the samma," this refers to a man wrapping himself in his garment in such a way that his hand cannot come out of it, so that he becomes like a solid rock (sakhrah samma) that has no opening in it.