Although I Agree with the previous definition, I would like to add a reference to the origin of the phrase.
The phrase itself became quite popular thanks to a Satiric TV show called Erez Nehederet (= Wonderful Country), In That show, we among other things followed up on a "Reality Show" called "Moskuna Project" talking about a
family called the Moskunas that has to compete each other in order to remain part of that
family. Every week, another member would be cast away from the
family until only one is left as the true Moskuna.
In this show, every time the
father was addressed by anyone his reply would always be "Leave me in your mother".