ʿAbdullah 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)."
عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ الْمُزَنِيِّ إِنِّي مِمَّنْ شَهِدَ الشَّجَرَةَ نَهَى النَّبِيُّ ﷺ عَنِ الْخَذْفِ