[Machine] O my son, hit your knees with your hands then I did it again after that by a day, and I prayed towards it and he slapped my hands. When he left, he said, "We used to do this and we were commanded to hit with the palms on the knees."  

يَا بُنَيَّ اضْرِبْ بِيَدَيْكَ رُكْبَتَيْكَ ثُمَّ فَعَلْتُهُ مَرَّةً أُخْرَى بَعْدَ ذَلِكَ بِيَوْمٍ فَصَلَّيْتُ إِلَى جَنْبِهِ فَضَرَبَ يَدِي فَلَمَّا انْصَرَفَ قَالَ «كُنَّا نَفْعَلُ هَذَا وَأُمِرْنَا أَنْ نَضْرِبَ بِالْأَكُفِّ عَلَى الرُّكَبِ»  

[Machine] About Mus'ab with his chain of narration regarding it.  

عَنْ مُصْعَبٍ بِإِسْنَادِهِ نَحْوَهُ  

[Machine] We have Abu Mas'ud Al-Ansari, who said, "Shall I not pray with you the prayer of the Messenger of Allah ﷺ ?" He then raised his voice, bowed, placed his hands on his knees, and spread his fingers until every part of him became still.  

لَنَا أَبُو مَسْعُودٍ الْأَنْصَارِيُّ أَلَا أُصَلِّي بِكُمْ صَلَاةَ رَسُولِ اللَّهِ ﷺ قَالَ «فَكَبَّرَ وَرَكَعَ وَوَضَعَ يَدَيْهِ عَلَى رُكْبَتَيْهِ وَفَرَّجَ بَيْنَ أَصَابِعِهِ حَتَّى اسْتَقَرَّ كُلُّ شَيْءٍ مِنْهُ»