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 ReferenceSahih Muslim / The Book of Mosques and Places of Prayer / Hadith: 546