Well done Grasshopper

I am looking for the origin of the phrase, 'Well done Grasshopper'.

I think it might have its origins in a television series that was shown in the British Isles in the early 1970s (presumably a bit earlier in its native US) called 'Kung Fu'. It was the story of a trainee monk/warrior, played by David Carradine, whose 'Kung Fu' name was 'Grasshopper'. His teacher (a blind monk) would say things like 'Well done, Grasshopper'.

It was not one of the greatest pieces of television ever made.

DFG