The Wandering Jew is a figure from Christian folklore. The
legend relates that a Jewish shoemaker, taunting Jesus on the way
to crucifixion, was told by him "thou shalt go on forever till I
return". The shoemaker was thus punished for his indiscretion by
being forced to wander the earth until the second coming of
Jesus.
Others trace it to the Matthew 16:28:
Verily I say unto you, There be some standing here, which shall not
taste of death, till they see the Son of man coming in his
kingdom
http://en.wikipedia.org/wiki/The_wandering_jew