2 Kings 18:27
But Rabshakeh said unto them, Hath my master sent me to thy master, and to thee, to speak these words? hath he not sent me to the men which sit on the wall, that they may eat their own dung, and drink their own piss with you?
And thou shalt eat it as barley cakes, and thou shalt bake it with dung that cometh out of man, in their sight
And shell fish is supposed to be unclean?