Why did the Prophet (peace be upon him) specify those who died in Madinah for intercession, and is there wisdom in that?

The Hadith encourages residing in Medina and remaining there until death, so that this may be a means of attaining the special intercession of the Prophet, peace and blessings be upon him, for whoever dies therein. It is therefore a command to commit to living there and not depart from it, so that this may be a cause for one to die therein.