[Machine] states that it is disliked to fold one's arms in front of them. It is narrated from Ibn Umar in one of the two narrations that he also disliked it, as did Mujahid and Ibrahim An-Nakha'i. It is mentioned from Jabir ibn Abdullah, then from Al-Hasan and Ibn Sireen that they did not see any harm in it, as if they allowed it for those who do it without thinking. But as for those who do it intentionally, it is prohibited. Ash-Shafi'i, may Allah have mercy on him, pointed to the meaning of this in the book of Al-Buwayti and used the wording of the hadith as evidence.  

أَنْ يَضُمَّ جَانِبَيْهِ بَيْنَ يَدَيْهِ فَإِنْ ضَمَّهُ فَلَيْسَ بِسَدْلٍ وَرُوِيَ عَنِ ابْنِ عُمَرَ فِي إِحْدَى الرِّوَايَتَيْنِ عَنْهُ أَنَّهُ كَرِهَهُ أَيْضًا مُجَاهِدٌ وَإِبْرَاهِيمُ النَّخَعِيُّ وَيُذْكَرُ عَنْ جَابِرِ بْنِ عَبْدِ اللهِ ثُمَّ عَنِ الْحَسَنِ وَابْنِ سِيرِينَ أَنَّهُمْ لَمْ يَرَوْا بِهِ بَأْسًا وَكَأَنَّهُمْ إِنَّمَا رَخَّصُوا فِيهِ لِمَنْ يَفْعَلُهُ لِغَيْرِ مَخِيلَةٍ فَأَمَّا مَنْ يَفْعَلُهُ بَطَرًا فَهُوَ مَنْهِيٌّ عَنْهُ وَقَدْ أَشَارَ الشَّافِعِيُّ رَحِمَهُ اللهُ إِلَى مَعْنَى هَذَا فِي كِتَابِ الْبُوَيْطِيِّ وَاحْتَجَّ بِمَتْنِ الْحَدِيثِ الَّذِي