The Messenger of Allah ﷺ said, "If you must do it, then only once."
أخبرنا سويد بن نصر قال أنبأنا عبد الله بن المبارك عن الأوزاعي عن يحيى بن أبي كثير قال حدثني أبو سلمة بن عبد الرحمن قال
أن رسول الله ﷺ قال إن كنت لا بد فاعلا فمرة
Bukhari transmitted it in the Book of Action in Prayer, chapter on wiping away pebbles during prayer, hadith no. 1207, and Muslim in the Book of Mosques, chapter on the dislike of wiping away pebbles and leveling the dust during prayer, hadith no. 546, from the hadith of Ibn Abu Kathir, with this wording. It is also in Al-Kubra, hadith no. 533.