I prayed by the side of my father. I put both of my hands between my knees(in bowing condition). He prohibited me from it. I then repeated; so he said: Do not do so, because we used to do so. But we were prohibited to do that, and commanded to put our hands on the knees.  

صَلَّيْتُ إِلَى جَنْبِ أَبِي فَجَعَلْتُ يَدَىَّ بَيْنَ رُكْبَتَىَّ فَنَهَانِي عَنْ ذَلِكَ فَعُدْتُ فَقَالَ لاَ تَصْنَعْ هَذَا فَإِنَّا كُنَّا نَفْعَلُهُ فَنُهِينَا عَنْ ذَلِكَ وَأُمِرْنَا أَنْ نَضَعَ أَيْدِيَنَا عَلَى الرُّكَبِ  

When any of you bows, he should spread his arms on his thighs and clap both his palms (Placing them between the knees), as if I am seeing the variation of the fingers of the Messenger of Allah ﷺ.  

إِذَا رَكَعَ أَحَدُكُمْ فَلْيَفْرِشْ ذِرَاعَيْهِ عَلَى فَخِذِهِ وَلْيُطَبِّقْ بَيْنَ كَفَّيْهِ فَكَأَنِّي أَنْظُرُ إِلَى اخْتِلاَفِ أَصَابِعِ رَسُولِ اللَّهِ ﷺ