It you must do so, do it only once.  

ذَكَرَ النَّبِيُّ ﷺ الْمَسْحَ فِي الْمَسْجِدِ يَعْنِي الْحَصَى قَالَ إِنْ كُنْتَ لاَ بُدَّ فَاعِلاً فَوَاحِدَةً  

“The Messenger of Allah ﷺ said, concerning smoothing the pebbles during prayer: ‘If you must do that, then do it only once.’”  

قَالَ رَسُولُ اللَّهِ ﷺ فِي مَسْحِ الْحَصَى فِي الصَّلاَةِ إِنْ كُنْتَ فَاعِلاً فَمَرَّةً وَاحِدَةً  

[Machine] The Prophet mentioned wiping in the mosque, meaning wiping over pebbles, and he said: "If you must do it, then only once."  

ذَكَرَ لِلنَّبِيِّ الْمَسْحَ فِي الْمَسْجِدِ يَعْنِي الْحَصَى فَقَالَ إِنْ كُنْتَ لَا بُدَّ فَاعِلًا فَوَاحِدَةً  

[Machine] It was said to the Prophet ﷺ , "Wiping the mosque meaning the pebbles." He said, "If you must do it, do it only once."  

قِيلَ لِلنَّبِيِّ ﷺ الْمَسْحُ فِي الْمَسْجِدِ يَعْنِي الْحَصَى فَقَالَ إِنْ كُنْتَ لَا بُدَّ فَاعِلًا فَوَاحِدَةً  

"I asked Messenger of Allah (S) about smoothening the pebbles during Salat. He said: 'If you must do so, then let it be only once.'" (Using translation from Tirmidhī 380)  

سَأَلْتُ رَسُولَ اللَّهِ ﷺ عَنْ مَسِّ الْحَصَى فِي الصَّلَاةِ فَقَالَ «إِنْ كُنْتَ لَا بُدَّ فَاعِلًا فَمَرَّةً»  

[Machine] The Messenger of Allah ﷺ said, "If you do it, do it once," meaning wiping off the pebbles.  

قَالَ رَسُولُ اللهِ ﷺ «إِنْ كُنْتَ فَاعِلًا فَمَرَّةً» يَعْنِي مَسْحَ الْحَصَى  

"إِنْ كُنْتَ لَابُدَّ فَاعلًا فَمَرَّةً وَاحدَةً" .