Does Pharson surname come from Lewis.

[anne]

I have got the death certificate from Scotlands People of my Grt Grt Grandfather John Morrison,it lists his parents as William Morrison and Mary Pharson,i have never come across this surname before and wonderd if anyone else has.Also would anyone have William and Mary in their tree,i never had Johns birth place but was told by my mother that he came from Lewis,i did find a birth of a John Morrison father named as William Morrison christned 6th October 1828 at Lochbroom,i cant find his birth certificate so how do i know if this is my Johns christening date.Anne.