Muslims believe Muhammad began receiving revelation sometime in the year 610 CE. Initially, the ranks of the Muslims only included Muhammad and some of his close friends and relatives. However, as more members of the Quraysh and other Arab tribes respected his words and accepted his message, the vast majority of them, including tribal leaders and some of his relatives, such as Abū Lahab, opposed, ridiculed and eventually boycotted his clan, the Banu Hashim, and Muhammad and his followers were harassed, assaulted and forced into exile in Abyssinia. After experiencing the "Isra" and "Mi'raj" in 620 and receiving delegations from Medina and pledges of protection from the two Arab tribes that lived in the city at al-'Aqabah, Muhammad instructed his companions to gradually migrate to the city, before doing so himself in 622.