Why did Mohammad migrate to Medina in 622 -?

Answer 1

The Muslims in Makkah had been horribly persecuted, some tortured to death, by the pagan Quraysh and other Makkan tribes. Prophet Muhammad was determined to stay in Makkah, but encouraged other Muslims to flee to Madinah, where the local people welcomed them and incorporated them into local society. In spite of the Quryash's hatred of the Muslims and of Prophet Muhammad, they continued to give him their money and valuables to keep safe in his house in Makkah. Finally the Muslims learned that the Quraysh planned to attack Prophet Muhammad in his home. He and his best friend, Abu Bakr, slipped out of Makkah at night and started to travel north to Madinah. Prophet Muhammad, though leaving Makkah to escape religious persecution, was worried about that the valubles he had been given to safeguard. His last act before leaving Makkah was to instruct his cousin and son-in-law, Ali, to return the money and valuables to the Quraysh, the same people who were trying to kill him. Ali did this, scrupulously.

Answer 2

The Makkans were idol worshippers. The last Prophet of Islam (SAW) started preaching the ONENESS (Tauheed) of Almighty Allah, that there was ONLY ONE Almighty God (Allah in Arabic) Who is the Sole Creator, Sustainer, Provider and Ruler of alll the worlds He has created, and that He has no Parents, No Son, No off-spring, No Associate whatsoever, the Makkans turned against. They tortured him and his followers to the extreme extent. Finally they planned to kill him. He was commanded by Almighty Allah to migrate to Madina where some of his followers had already migrated. He loved his place of birth, Makka Mukarma, but it was made impossible for him to stay there any longer. The Makkans forced him to flee to Madina. This migration or flight is callaed Hijrat.