originally Said: "Be(in) Ima(mother) Scha(yours)".the source of this phrase is in the sentence "I Swear in my mother" or "Do you swear in your mother?"
"I didnt Break the Vase! in my mother!"
as a tester:
Joe:Who ate my Cookie?
Jeff:It Wasnt me!
Joe:In your mother?
as a convincing method:
Gimme a Shekel! in your Mother!