Sayyiduna Jabir (may Allah be pleased with him) narrates that before his death, the Messenger of Allah (peace and blessings be upon him) wrote letters to Chosroes, Caesar, the Negus and every stubborn, arrogant tyrant (ruler).
Hadith Referenceالمعجم الأوسط / باب الميم / 8976
Hadith Takhrij«أخرجه أحمد فى «مسنده» (6/3088) [دون رقم في الترقيم المختار]»