Al-Baihaqi, on the authority of Ibn Ishaq, gave the following narration of the Prophet’s letter sent to Negus:
"This letter is sent from Muhammad, the Prophet to Negus Al-Ashama, the king of Abyssinia (Ethiopia).
Peace be upon him who follows true guidance and believes in Allâh and His Messenger. I bear witness that there is no god but Allâh Alone with no associate, He has taken neither a wife nor a son, and that Muhammad is His slave and Messenger. I call you unto the fold of Islam; if you embrace Islam, you will find safety,
"Say (O Muhammad ): ‘O people of the Scripture (Jews and Christians), come to a word that is just between us and you, that we worship none but Allâh, and that we associate no partners with Him, and that none of us shall take others as lords besides Allâh.’ Then, if they turn away, say: ‘Bear witness that we are Muslims.’ " [The Noble Qur'an 3:64]
Should you reject this invitation, then you will be held responsible for all the evils of the Christians of your people."
Dr. Hameedullah (Paris), a reliable verifier, has adduced a version of the above letter disclosed only a short time ago and identical to Ibn Al-Qaiyim’s narration. Dr. Hameedullah exerted painstaking effort and used all means of modern technology to verify the text of the letter, which reads as follows:
"In the Name of Allâh, the Most Beneficent, the Most Merciful.
From Muhammad the Messenger of Allâh to Negus, king of Abyssinia (Ethiopia). Peace be upon him who follows true guidance. Salutations, I entertain Allâh’s praise, there is no god but He, the Sovereign, the Holy, the Source of peace, the Giver of peace, the Guardian of faith, the Preserver of safety. I bear witness that Jesus, the son of Mary, is the spirit of Allâh and His Word which He cast into Mary, the virgin, the good, the pure, so that she conceived Jesus. Allâh created him from His spirit and His breathing as He created Adam by His Hand. I call you to Allâh Alone with no associate and to His obedience and to follow me and to believe in that which came to me, for I am the Messenger of Allâh. I invite you and your men to Allâh, the Glorious, the All-Mighty. I hereby bear witness that I have communicated my message and advice. I invite you to listen and accept my advice. Peace be upon him who follows true guidance."
[Za'd Al-Ma'ad 3/60]