If you're married and Jewish, the wife's mother keeps the marriage document, so even if there is a house fire and all documents are lost, your mother in law usually lives in another house, so you can pick it up from there.

I’m married and Jewish. It would be pretty surprising to me if my wife’s mother had even seen our marriage paperwork let alone possessed it. This also isn’t a tradition I’ve ever heard of in my family.

Or did a joke about overbearing mother in laws just go right over my head.