Truth’s a dog must to kennel; he must be whipped out, when Lady the brach may stand by the fire and stink.

– William Shakespeare

King Lear, Act 1, Scene 4. This is the Fool’s reply when King Lear reminds him that he can whip him for his cheekiness. The Fool retorts that he gets whipped like a dog for speaking the truth, while Lady Bitch can stay by the fire and stink. A metaphor is used to compare truth to a dog.