بِسْمِ اللّٰهِ الرَّحْمَنِ الرَّحِيمِ. مِنْ مُحَمَّدٍ عَبْدِ اللّٰهِ وَرَسُولِهِ إِلَى هِرَقْلَ عَظِيمِ الرُّومِ. سَلاَمٌ عَلَى مَنِ اتَّبَعَ الْهُدَى، أَمَّا بَعْدُ فَإِنِّي أَدْعُوكَ بِدِعَايَةِ الإِسْلاَمِ، أَسْلِمْ تَسْلَمْ، يُؤْتِكَ اللّٰهُ أَجْرَكَ مَرَّتَيْنِ، فَإِنْ تَوَلَّيْتَ فَإِنَّ عَلَيْكَ إِثْمَ الأَرِيسِيِّينَ وَ{یٰۤاَہۡلَ الۡکِتٰبِ تَعَالَوۡا اِلٰی کَلِمَۃٍ سَوَآءٍۢ بَیۡنَنَا وَبَیۡنَکُمۡ اَلَّا نَعۡبُدَ اِلَّا اللّٰہَ وَلَا نُشۡرِکَ بِہٖ شَیۡئًا وَّلَا یَتَّخِذَ بَعۡضُنَا بَعۡضًا اَرۡبَابًا مِّنۡ دُوۡنِ اللّٰہِ ؕ فَاِنۡ تَوَلَّوۡا فَقُوۡلُوا اشۡہَدُوۡا بِاَنَّا مُسۡلِمُوۡنَ}
“In the name of Allah, the Gracious, the Merciful.
“From Muhammad, the servant of Allah and His Messenger
“To Heraclius, the emperor of Byzantine
“Peace be upon those who follow the Guidance.
“Furthermore, I invite you to Islam; embrace Islam and you will find peace, and Allah will reward you twofold. However, if you turn away, you will also bear the sin of ’Arisiyyin [your subjects].
“And ‘O People of the Book! come to a word equal between us and you — that we worship none but Allah, and that we associate no partner with Him, and that some of us take not others for Lords beside Allah.’ But if they turn away, then say, ‘Bear witness that we have submitted [to God].’ [Surah Aal-e-Imran, Ch.3: V65].”
(Sahih al-Bukhari, Kitab bad’i l-wahy, Hadith 7)