In 622 Heraclius probably in concert with Aksum launched a campaign against Khosrau. It is no coincidence that this is also the year in which that the Arabs consider their independence began. In the 660s, Sebeos tells us that when Heraclius captured Edessa in the 620s the Jews fleeing from Edessa claimed asylum in the New Medina (possibly the Negev of Beersheba or Wadi Rafidain) but initially failed to win any allies to their cause until Judaizing the Ishmaelites into HaGarim on the ideas of a learned Mahmet scholar who arrived in the New Medina later that year. Thus this became the year the Believers (Jews, Nestorians and Sabians) settled their case. The first year of the Arabs.

A Sabi (Baptist) did present the faith to Heraclius as the Hadiths claim. But there was no leader by the name of Muhammad mentioned the Byzantine version of the story. https://sunnah.com/bukhari/1/7