"The Messenger of Allah ﷺ said: 'When any one of you stands in prayer, let him not smooth the pebbles, for he is facing Mercy.'"  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا قَامَ أَحَدُكُمْ فِي الصَّلاَةِ فَلاَ يَمْسَحِ الْحَصَى فَإِنَّ الرَّحْمَةَ تُوَاجِهُهُ