Edit: it may have not been entirely clear. Im talking about the spesific belief that jews are trying to outsmart god.

People who say that jews have found a way to "trick god" simply dont have an understanding of jewish law.

It is also just a stereotype to add to the antisemitic sentiment that jews are always try to trick people and benefit off of others.

edit: It might somtiemes play into antisemitic tropes is what the author meant to say

What really going on in jewish law is that rabbis have read the torah and created spesific laws based on the text of what you can or can not do. And its always taking the most extreme interpretation of the text, but then they also allowed stuff based on the interpretation. Ans then what happens is people who dont understand anything say that god told them to do something and they just created a shortcut to "trick" god.