What type of figurative language is "don't bite the hand that feeds you"

which book is it because i might knoe the anwser

the negative way that it shaped life was by having a feudal system where only the nobles and the christian church while it was oppressive to the peasants and specially to women. the positive way that it shape life is by introducing the artisan class when the feudal system fell. it change the attitudes towards religion and it also introduced what was known as knightly chivalry.

-hope this : )