Jumping jehosephat

Does anyone know where the phrase jumping jehosephat came from?

Since nobody has so far, on this forum, been able to give a satisfactory answer to your question I propose in the words of Churchill (1874 - 1965) to classify it as '.a riddle wrapped in a mystery inside an enigma'.

Except, of course, that Jehosephat was a king in the Bible.

The real riddle remains: why was he jumping and what provoked him so to do?

I have read over the stories in the bible that discuss Jehosephat and none of them refer to him jumping. Maybe it is a riddle wrapped in a mystery
inside an enigma. ksc