The Messenger of Allah ﷺ said, "Whatever two people exchange when insulting one another falls upon the one who started it, so long as the wronged party does not exceed the bounds."
حدثنا ابن أبي عدي عن شعبة عن العلاء ومحمد بن جعفر حدثنا شعبة قال سمعت العلاء يحدث عن أبيه
قال رسول الله ﷺ المستبان ما قالا فعلى البادئ ما لم يعتد المظلوم
Its isnad is sahih. Bukhari related it in Adab al-Mufrad 62-63, and Muslim 2:285, both by way of Ismail bin Jafar, and Abu Dawud 4894, Awn al-Mabud 4:425, by way of Darawardi, and Tirmidhi 3:139, also by way of Darawardi, both of them from Ala, with this isnad, similarly. Tirmidhi said, This is a hasan sahih hadith. It is also found in Targheeb wal-Tarheeb 3:285.Al-mustabban, with a doubled ba, means the two who curse and revile each other. "So long as he does not exceed the bounds," in the manuscript it appears as "so long as he does not transgress," with the ya kept at the end of the verb.