מדרש על משלי 29:7

(Fol. 155b) R. Jonah expounded in front of the house of the Prince of the Exile: "What is meant by the passage (Pr. 29, 7.) The righteous considereth the cause of the indigent, i.e., the Holy One, praised be He! knoweth that a dog has not enough food and therefore ordained that the food shall remain in his stomach (undigested) for three days."