Sayyiduna Imran bin Husayn (may Allah be pleased with him), or perhaps Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him), narrates: The Prophet (peace and blessings be upon him) said: "Beware of flicking pebbles, for it breaks a tooth or gouges out an eye, and it does not harm the enemy." (Allamah al-Haythami says:) I say: This report is recorded in the "Sahih" as a hadith narrated from Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him).
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains a narrator, al-Hasan bin Dinar, and he is da'if (weak).