What in the Blue Jesus

Hope this doesn't offend...

My Great Aunt used to say "What in the Blue Jesus?"

Have you heard it? Where does it come from?

cmonkey

This a total pre-research off-the-wall guess. I wonder if it has to do with someone mishearing another oath -- what in the pluperfect *** are you doing.

Merriam-Webster

Main Entry: plu·per·fect
Pronunciation: "plü-'p&r-fikt
Function: adjective
Etymology: Middle English pluperfyth, modification of Late Latin plusquamperfectus, literally, more than perfect
1 : PAST PERFECT
2 : utterly perfect or complete
- pluperfect noun