He further said, “This hadith is fair and singular through this chain.

A group of scholars maintained that news of the Romans’ victory over Persia arrived on the day of Badr, while others held that it was on the day of al-Hudaybiyyah—and this is the correct view. Heraclius had walked from Ḥimṣ to Bayt al-Maqdis (Jerusalem) on foot in gratitude to Allah for granting him victory over the Persians. It was then that the Prophet’s letter, carried by Dihyah al-Kalbi and inviting him to Islam, reached him shortly after Allah’s granting the Romans victory over Persia. The Prophet, peace and blessings be upon him, and the believers with him rejoiced at this.

The scholars of sīrah (prophetic history) relate: When the Romans prevailed and Heraclius, the emperor of Rome, left his residence in Ḥimṣ, he walked on foot to Bayt al-Maqdis in thanksgiving to Allah.