My usually dependable sources indicate only that the phrase is an Americanism of recent origin. I suppose not attention has been paid to it since it's readily decipherable as to meaning...
Again, I Thank Ye! I am but the King of a very Small Province in the American Southwest,
known to some as Arizona . . . . . certainly
no Powerful Head of State!
Well, here's me living in the northern Rockies thinking I've finally stumbled across Royalty... but no! Well, I lived in your fair State where the motto is "Yes, but it's a dry heat"...