What’s with the Hebrew Expression “To Jump over One’s Bellybutton”?

Avi Rockoff writes:

On my last visit to Israel, I learned of the Hebrew expression likpots me’al ha-pupik [literally, “to jump over one’s bellybutton”], which apparently means something like “to go off half-cocked.” Do you know anything about the origin of this colorful but curious expression? I don’t believe it comes from Yiddish, which to the best of my knowledge has nothing like it.

It’s not clear if Yiddish does or doesn’t have anything like it. In his comprehensive Hebrew slang dictionary Milon ha-Sleng ha-Makif, Ruvik Rosenthal, Israel’s leading expert on the subject, traces likpots me’al ha-pupik to a Yiddish predecessor shpringen ibern pupik. Yiddish speakers I know tell me they are unfamiliar with such an idiom. An alternative origin has been suggested in the Russian proverb vyshe golovy ne prignesh, “You can’t jump over your own head”—that is, there are some things that are impossible to do. Jumping over one’s bellybutton wouldn’t be much easier.