The Messenger of Allah ﷺ said, "Whoever is killed defending against an injustice done to him is a martyr."
أخبرنا القاسم بن زكريا بن دينار قال حدثنا سعيد بن عمرو الأشعثي قال حدثنا عبثر عن مطرف عن سوادة بن أبي الجعد عن أبي جعفر قال كنت جالسا عند
قال رسول الله ﷺ من قتل دون مظلمته فهو شهيد
[Sahih] Tabarani narrated it in Kabir: 7/86, hadith: 6454, from the hadith of Saeed bin Amr, from him, and it is in Kubra, hadith: 3559. Abshar is Ibn Qasim, and Mutarrif is bin Tarif, and Sawadah is obscure, and Abu Jafar is of unknown status, not deemed reliable by anyone except Ibn Hibban, and the hadith has corroborating narrations.