In this hadeeth, the Prophet (peace and blessings of Allah be upon him) said, “Faith retreats to Madeenah like a snake returns to its hole.” The word “retreats to” means to return and settle in Madeenah, just as a snake, when it goes out from its hole, returns to it. Here the Prophet (peace and blessings of Allah be upon him) was saying that this religion will retreat to Madeenah after all other countries become corrupt, just as a snake comes out of its hole and wanders about the land, then it goes back to its hole. 

This hadeeth also indicates that just as Islam spread from Madeenah, it will return to it. Islam with its strength and authority spread from Madeenah, although its roots stemmed from Makkah. Makkah was the place where the first Revelation came down, but the Muslims did not have a state and power, and engage in jihad (battle), until after they migrated to Madeenah. Hence Islam with its power and authority, spread from Madeenah and will retreat to it at the end of time. 

Some of the scholars said: this hadeeth refers to something that has already happened, i.e., the people came in delegations to Madeenah and went back there again to learn about sharee’ah (Islamic law) and the teachings of Islam from the Messenger of Allah (peace and blessings of Allah be upon him). But the first meaning is the apparent meaning of the hadeeth and is more correct.