Source of the expression that sounds like "Jee-hossey-fat"

Solution 1:

Jehoshaphat is the name of a King of Judah. As an exclamation has probably become popular as a euphemism for Jesus:

• A king of Judah in the mid 9th century bc.

• As exclamation (also jumping Jehoshaphat) A mild expletive: Jehoshaphat! That would be ghastly (Probably a euphemism for Jesus)

(ODO)

The biblical king Jehoshaphat:

• is the inspiration for the exclamation “jumpin’ Jehosaphat!” This alliterative idiom probably arose in the 19th century but was popularized by the cartoon character Yosemite Sam in the 20th century.

(www.waywordradio.org)

Why is Jehoshaphat described as jumping?

• It goes back to a prophecy which Israel’s king David uttered, explaining about how God works with people:

  • With the merciful You will show Yourself merciful; With the blameless man You will show Yourself blameless; With the pure You will show Yourself pure; And with the devious You will show Yourself shrewd. You will save the humble [afflicted] people; But Your eyes are on the haughty, that You may bring them down.

(2 Samuel 22:26-28)

• That scripture is being fulfilled once again in our day in Iraq! But the above prophecy goes on:

  • For You are my lamp, O Lord; The Lord shall enlighten my darkness. For by You I can run against a troop; By my God I can leap over a wall.

(2 Samuel 22:29-30)

• And that’s what Jehoshaphat did, metaphorically speaking. He ‘jumped’ on that occasion because of the supernatural help of God.