عَنْ أَبِي ذَرٍّ رَضِيَ اللَّهُ عَنْهُ يَبْلُغُ بِهِ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((إِذَا قَامَ أَحَدُكُمْ إِلَى الصَّلَاةِ فَإِنَّ الرَّحْمَةَ تُوَاجِهُهُ فَلَا يَمْسَحِ الْحَصَى (وَفِي رِوَايَةٍ) فَلَا يُحَرِّكِ الْحَصَى، أَوْ لَا يَمَسَّ الْحَصَى))
It is narrated from Sayyiduna Abu Dharr (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: When any of you stands for prayer, he should not clear the pebbles, nor move them, nor touch them, because mercy is before him.