Mu'aiqib quoted the Apostle of Allah (ﷺ) mentioning the removal of pebbles from the ground where he prostrated himself. He (the Prophet) said: It you must do so, do it only once.
Hadith Referenceصحيح مسلم / كتاب المساجد ومواضع الصلاة / 546
Mu'aiqib said: They asked the Apostle (صَلَّی اللَّهُ عَلَيْهِ وَسَلَّمَ) about the removal of (pebbles) in prayer, whereupon he said: If you do it, do it only once.
Hadith Referenceصحيح مسلم / كتاب المساجد ومواضع الصلاة / 546