Question about Rabbi Shulem’s Line in the Shtisel Finale – Isaac Bashevis Singer Quote?

In the final scene of Shtisel, Rabbi Shulem says that he heard Bashevis Singer said: "The dead don’t go anywhere. They’re all here. Each man is a cemetery. An actual cemetery, in which lie all our grandmothers and grandfathers, the father and mother, the wife, the child. Everyone is here all the time."

I’m curious if this is a direct quote from Isaac Bashevis Singer or if it’s something the writers crafted to reflect his themes. I couldn’t find any source for it. Has anyone come across this line in Singer’s work?