The Messenger of Allah ﷺ said, "When two people exchange insults, the sin of what they say falls upon the one who started it, unless the wronged party exceeds the proper limit in response."
حدثنا قتيبة حدثنا عبد العزيز بن محمد عن العلاء بن عبد الرحمن عن أبيه
أن رسول الله ﷺ قال المستبان ما قالا فعلى البادي منهما ما لم يعتد المظلوم
Its isnad is sahih. Abu Dawud narrated it in "Manners," chapter "Two people cursing one another," no. 4894, from the hadith of Abdul-Aziz Darawardi, and Muslim, no. 2587, from the hadith of Ala bin Abdul-Rahman, both through the same route.On this subject there is also a narration from Saad [Ibn Majah, no. 3941], from Ibn Masud [coming up, no. 1983], and from Abdullah bin Mughafal [Tabarani in Al-Awsat, 1/413, no. 738].