Sunan an-Nasa'i 1191
سنن النسائي#1191Da'ifأَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، وَالْحُسَيْنُ بْنُ حُرَيْثٍ، - وَاللَّفْظُ لَهُ - عَنْ سُفْيَانَ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي الأَحْوَصِ، عَنْ أَبِي ذَرٍّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا قَامَ أَحَدُكُمْ فِي الصَّلاَةِ فَلاَ يَمْسَحِ الْحَصَى فَإِنَّ الرَّحْمَةَ تُوَاجِهُهُ " .
It was narrated that Abu Dharr said:"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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahDaif
Al-AlbaniDaif
Zubair Ali ZaiHasan
In-book reference: 13:13