It wasnarrated that Abu Hurairah said:
The Messenger of Allah (ﷺ)said:"Whoever smoothes the pebbles, then he has engaged in Laghw."* (RU)
English reference (RU): Vol. 1, Book 5, Hadith 1025 (RU)
Arabic reference (RU): Book 5, Hadith 1078 (RU)