The Holy Qur’an does not provide any support to the concept of banning non-Muslims from the Holy cities of Makkah and Madinah.
During the time of the Holy Prophet(sa), after the victory over Makkah by the Muslims, even idolaters lived in the city and many others frequently visited to hold discussions with the Holy Prophet(sa) without being subjected to any discrimination based on their faith. An incident during the life of the Holy Prophet(sa) reveals that a deputation from a Christian tribe visited him in Medina to discuss religious affairs. When the deputation was about to leave the mosque to hold its’ religious services at another location, the Holy Prophet(sa) said:
“There is no need for you to go out of the mosque, because the mosque is the place to worship one God, if you want to do so, you have every freedom of worship, and holding the services in it” (Zurqani).
This reveals that Islam permits non-Muslims into the Holy cities of Makkah and Madinah and current policies that undermine this are a result of political rather than Islamic regulations.