Where do you get TM dig?
depends what version ur playing...
in ruby and sapphire u can get it on route 114. and emerald MIGHT be the same.
in leafgreen and firered u can get it in cerulean city in the celadon mart.
and in diamond and pearl u can find it on route 214.in emerald you get from the Fossil Maniacs little brother, its probably the same in Ruby and Sapphire