A palmer was a person who wore crossed palm leaves to signify the person had made a pilgrimage to the holy land. Such persons were held in especial reverence during the middle ages, given almost the status of holy orders.

Obviously the two songs have been intermingled over the years. I suspect The Maid and the Palmer has its origins in the biblical story of Jesus and the woman at the well, but I never interpreted the palmer as being anyone but a citizen given a mantle of holiness by his circumstances.