Hooray urban legend

Hi!
I hear an urban legend that 'hooray', according to English etym.
dictionaries from German 'hurra', is from an Aramaic or Hebrew
exclamation meaning 'kill/slughter' or the like and refers to some
event involving John the Baptist. I don't have access to a German
(or Swedish hononym which presumably has the same source) that contains
the entry and I can't verify is in an Aramaic or Hebrew dictionary.
Anyone know the status?
thanks,
Harald