It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them) that the king of Rome, Heraclius, summoned Sayyiduna Abu Sufyan (may Allah be pleased with him), then he asked for the letter of the Messenger of Allah (peace and blessings be upon him) that had been sent to him. This letter the Prophet (peace and blessings be upon him) had instructed Sayyiduna Dihyah Kalbi (may Allah be pleased with him) to give to the governor of Busra, so he delivered it to Heraclius, and he read it. In it was: «بسم الله الرحمن الرحیم» ...... From the servant of Allah and His Messenger, Muhammad, to Heraclius, the king of Rome. Peace be upon him who follows guidance. Verily, I invite you to Islam. Accept Islam, you will be safe, and Allah the Exalted will grant you a double reward, and if you refuse, then the sin of your subjects will be upon you. And O People of the Book, come to a word that is equitable between us and you ...... you will bear witness that we are Muslims.
Hadith Referenceالادب المفرد / كتاب أهل الكتاب / 1109
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه البخاري ، كتاب بدء الوحي : 7 و مسلم : 1773»