Narrated `Uqba bin Sahban:
`Abdullah bin Mughaffal Al-Muzani who was one of those who witnessed (the event of) the tree, said, "The Prophet (ﷺ) forbade the throwing of small stones (with two fingers)." (DE)
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 365 (DE)
Arabic reference (DE): Book 65, Hadith 4841 (DE)