The Prophet ﷺ forbade Ishtimal-as-Samma' and that a man should sit in an Ihtiba' posture in one garment, nothing of which covers his private parts.  

عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ ؓ أَنَّ النَّبِيَّ ﷺ نَهَى عَنِ اشْتِمَالِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي ثَوْبٍ وَاحِدٍ لَيْسَ عَلَى فَرْجِهِ مِنْهُ شَىْءٌ  

"The Messenger of Allah [SAW] forbade Ishtimal As-Samma' and wrapping oneself in a single garment (that did not cover the private parts)."  

نَهَى رَسُولُ اللَّهِ ﷺ عَنِ اشْتِمَالِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي ثَوْبٍ وَاحِدٍ لَيْسَ عَلَى فَرْجِهِ مِنْهُ شَىْءٌ  

"The Messenger of Allah [SAW] forbade Ishtimal As-Samma' and wrapping oneself in a single garment (that did not cover the private parts)." (Using translation from Nasāʾī 5340)  

نَهَى رَسُولُ اللهِ ﷺ عَنْ اشْتِمَالِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي ثَوْبٍ وَاحِدٍ لَيْسَ عَلَى فَرْجِهِ مِنْهُ شَيْءٌ  

"The Messenger of Allah [SAW] forbade Ishtimal As-Samma' and wrapping oneself in a single garment (that did not cover the private parts)." (Using translation from Nasāʾī 5340)  

نَهَى رَسُولُ اللهِ ﷺ عَنْ اشْتِمَالِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي ثَوْبٍ وَاحِدٍ لَيْسَ عَلَى فَرْجِهِ مِنْهُ شَيْءٌ  

Messenger of Allah ﷺ forbade Ishtimal-As-Samma' (wrapping one's body with a garment so that one cannot raise its end or take one's hand out of it). He also forbade Al-Ihtiba' (sitting on buttocks with knees close to ʿAbdomen and feet apart with the hands circling the knees) while wrapping oneself with a single garment, without having a part of it over the private parts. (Using translation from Bukhārī 367)  

«نَهَى رَسُولُ اللهِ ﷺ عَنِ اشْتِمَالِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي ثَوْبٍ وَاحِدٍ لَيْسَ عَلَى فَرْجِهِ مِنْهُ شَيْءٌ»