The Madinan Period II, Part 8: The Battle of Muʾtah and the Letters to the Kings
Section 13 of 15 · The Life of the Prophet Muhammad: The Madinan Period, Part Two
The Letter and What Followed
The letter was brought and read: from Muḥammad, the Messenger of Allah, to Hiraql, the great one of the Romans. Peace be to those who follow the guidance. I call you to believe in Islam: adopt Islam and you will be safe, and Allah will give you double the reward. If you decline, you shall bear the responsibility of the Arīsiyyūn. The Arīsiyyūn, as Ibn Ḥajar says, are the farmers: the Romans were a farming people. So the Messenger of Allah (peace be upon him) is telling him that he would bear responsibility for their disbelief.
After the letter was read, Abū Sufyān said: when he had said what he said and finished reading the letter, the noise became loud, and we were driven out. I then told my companions, when we had been driven out: this affair of Ibn Abī Kabshah — this is the name they used to call Muḥammad (peace be upon him) by — this affair of Ibn Abī Kabshah has got to the point where he even scares the king of those of pale skin. Thereafter I was convinced that he would prevail, and eventually Allah drew me into Islam. Because he saw that the Romans themselves were worried about Muḥammad (peace be upon him) — and these are the People of the Scripture; these are the people who understand prophethood.
Let us look at the letter, and some comments from Ibn Ḥajar. What title did the Messenger of Allah (peace be upon him) use to refer to Hiraql? He did not say the Roman emperor. Ibn Ḥajar says he was referred to as the great one of the Romans. Ibn Ḥajar says he was not given the title of king or leader because he is discharged according to the rule of Islam: Islam does not recognise his kingdom, and does not recognise his authority, and does not recognise the authority of any disbeliever. But, Ibn Ḥajar says, he was given a title, a cordial title: the great one of the Romans. And then, in the letter, the Messenger of Allah (peace be upon him) did not give him salām directly, but said: peace be upon those who follow guidance; and since they do not follow guidance, the Messenger of Allah (peace be upon him) did not give them salām — and that is because salām is not given to the unbelievers.
Ibn Ḥajar also mentions that Abū Sufyān said, when the letter of Muḥammad (peace be upon him) was read to Hiraql: I saw sweat falling from his forehead. That was how heavy the letter of the Messenger of Allah (peace be upon him) was. He knew that this was the truth, but he did not want to follow it. And there is a story mentioned in the books of sīrah that Hiraql called his patriarchs and told them: we should become Muslim; this is the prophet we were foretold of in our books. And they all roared and became angry. And then Hiraql told them: calm down; I just wanted to test your faith. So Hiraql wanted to become Muslim, but when he saw the reaction of his people, he told them: I was just testing you. And then he said — and another narration says he was saying this to the one who carried the letter — if I knew that I would be able to reach Muḥammad, I would have done so. He feared for his kingdom, and therefore, obviously, his intentions do not help him, because he did not truly become Muslim. This is the story of the letter to Hiraql.