Jerry Lewis Freestyle Raps ... IN YIDDISH!!!

6/9/2013 5:30 AM PDT

Jerry Lewis Freestyle Raps ... IN YIDDISH!!!

EXCLUSIVE

Jerry Lewis
has mad Yiddish flow ... or maybe it's mad gibberish flow ... either way, it was definitely an attempt at a freestyle rap ... and TMZ has the footage.

The 87-year-old legend unleashed his skillz last week in between shooting scenes for his movie "Max Rose" -- when he injected himself into a rap battle with "America's Got Talent" sensation Chris La Vrar (who just happened to be on the set that day).

Lewis -- impressed with La Vrar's rhymes -- replied, "Very good. Very, VERY good ... I want to do one now in Jewish."

The crowd laughs -- but Jerry was SERIOUS -- and busts out a rap that you've just GOT to hear ... especially if you're a Yiddish scholar ... because then you can tell us what he says.

Seriously, we tried to make out the words ... but no dice.

So ... help?