The prophet, peace be upon him, did have a “wet-nurse” named Haleema, when he was an infant and stayed with her for a number of years.
It was the custom of the people living in the villages to have someone out in the countryside nurse and care for their infants.
I wonder if it was so the children would grow up in a less poluted enviornment?
Perhaps they were worried about the effects of the “big city” on their youth? http://www.islamonline.net/livedialogue/english/Browse.asp?hGuestID=FH5Nti
who has time to think abt all tht…