It was narrated from 'Abdullah bin 'Umar that:

He saw a man moving pebbles with his hand while praying. When he finished, 'Abdullah said to him: "Do not move the pebbles while you are praying, for that is from Shaitan. Rather do what the Messenger of Allah ﷺ used to do." He said: "What did he used to do?" He said: "He would put his right hand on his right thigh, and point with the finger that is next to the thumb toward the Qiblah, and he would look at it, or thereabouts." Then he said: "This is what I saw the Messenger of Allah ﷺ doing."

أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، - وَهُوَ ابْنُ جَعْفَرٍ - عَنْ مُسْلِمِ بْنِ أَبِي مَرْيَمَ، عَنْ عَلِيِّ بْنِ عَبْدِ الرَّحْمَنِ الْمَعَافِرِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ رَأَى رَجُلاً يُحَرِّكُ الْحَصَى بِيَدِهِ وَهُوَ فِي الصَّلاَةِ فَلَمَّا انْصَرَفَ قَالَ لَهُ عَبْدُ اللَّهِ لاَ تُحَرِّكِ الْحَصَى وَأَنْتَ فِي الصَّلاَةِ فَإِنَّ ذَلِكَ مِنَ الشَّيْطَانِ وَلَكِنِ اصْنَعْ كَمَا كَانَ رَسُولُ اللَّهِ ﷺ يَصْنَعُ . قَالَ وَكَيْفَ كَانَ يَصْنَعُ قَالَ فَوَضَعَ يَدَهُ الْيُمْنَى عَلَى فَخِذِهِ الْيُمْنَى وَأَشَارَ بِأُصْبُعِهِ الَّتِي تَلِي الإِبْهَامَ فِي الْقِبْلَةِ وَرَمَى بِبَصَرِهِ إِلَيْهَا أَوْ نَحْوِهَا ثُمَّ قَالَ هَكَذَا رَأَيْتُ رَسُولَ اللَّهِ ﷺ يَصْنَعُ .