Targum zu Schemot 40:8

And thou shalt place the court round about, because of the merit of the fathers of the world, which encompasseth the people of the house of Israel round about. And thou shalt set the hanging of the gate of the court on account of the merit of the mothers of the world, which spreadeth at the gate of Gehennam, that none may enter there of the souls of the children of the people of Israel.