It wasnarrated from Sa'eed bin Jubair that a relative of 'AbdullahbinMughaffal threw some small pebbles. He told him not to do that andsaid:
"The Prophet (ﷺ) forbade throwing small pebbles and said:'They do not kill any game nor hurt the enemy, but they can break atooth or put out an eye.'" He did it again, and he ('Abdullah)said:"I tell you that the Prophet (ﷺ) forbade that and then yougo and doit again? I will never speak to you again."
English reference: Vol. 4, Book 28, Hadith 3226
Arabic reference: Book 28, Hadith 3348