The Messenger of Allah ﷺ forbade two ways of wearing a garment.The first is the Samma wrap, which means a person drapes his garment over one shoulder, leaving the other side of his body exposed with nothing covering it.The second is sitting with one's garment wrapped around the knees while drawn up against the body, with nothing covering the private parts beneath it.
نهى رسول الله ﷺ عن لبستين، واللبستان: اشتمال الصماء، والصماء: أن يجعل ثوبه على أحد عاتقيه، فيبدو أحد شقيه ليس عليه ثوب. واللبسة الأخرى: احتباؤه بثوبه وهو جالس، ليس على فرجه منه شيء.
Bukhari narrated it in the Book of Clothing (5820), and this is his wording, and Muslim narrated it in the Book of Trade (1512) except that he did not mention the explanation of the two garments. Both narrated it through Yunus, from Ibn Shihab, who said, Amir bin Saad informed me, that Abu Saeed Khudri informed him, and he related the hadith.The Hafiz said, The apparent wording of Bukhari's account indicates that the explanation mentioned in it is marfu, and this agrees with what the jurists have said. Even supposing it to be mawquf, it is still authoritative according to the sahih view, because it is an explanation given by the narrator that does not contradict the apparent meaning of the report. Fath al-Bari (1/477).His statement, "so one of his sides becomes exposed," means that his private part becomes exposed.It has also been said that sammaa is the same as the ishtimal of the Jews, and the prohibition of that has come in the hadith of Ibn Umar, so sammaa and the ishtimal of the Jews carry the same meaning. Sammaa is spelled with the plain, undotted sad, and with an elongated vowel.The linguists said, It means that a person covers his whole body with the garment, not raising any side of it, and leaving no opening through which he could take out his hand.Ibn Qutayba said, It is called sammaa because it blocks all the openings, so it becomes like a solid rock that has no crack in it.The jurists said, It means that a person wraps himself in the garment, then raises it from one of its sides and places it on his shoulder, so that his private part becomes exposed.Nawawi said, According to the explanation of the linguists, this would be disliked, lest some need arise for him and he find it difficult to free his hand, causing him harm. According to the explanation of the jurists, it is forbidden because it exposes the private parts. See Fath al-Bari (1/477).