1) The Muslims in Mecca faced severe persecution from the Quraysh tribe, which tried to limit the spread of Islam and control Muslim migration. 2) Due to the persecution, the Prophet Muhammad received a revelation from God telling him to migrate to Yathrib, later known as Medina, where Muslims would be protected. 3) In 622 CE, the Prophet Muhammad and Abu Bakr secretly left Mecca and made the journey on foot to Yathrib, marking the beginning of the Hijra, or migration, and the start of the Muslim calendar. This migration established the first permanent Muslim community free from persecution.