Ibn ‘Umar saw a man resting on his left hand while he was sitting during prayer. The version of Harun b. Zaid goes: He was lying on his left side. the agreed version goes: he said to him: Do not sit like this, because those who are punished sit like this.
أَنَّهُ رَأَى رَجُلاً يَتَّكِئُ عَلَى يَدِهِ الْيُسْرَى وَهُوَ قَاعِدٌ فِي الصَّلاَةِ وَقَالَ هَارُونُ بْنُ زَيْدٍ سَاقِطًا عَلَى شِقِّهِ الأَيْسَرِ ثُمَّ اتَّفَقَا فَقَالَ لَهُ لاَ تَجْلِسْ هَكَذَا فَإِنَّ هَكَذَا يَجْلِسُ الَّذِينَ يُعَذَّبُونَ