But what is the source of this hardness? It comes from gluttony and drunkenness. Who says so? Moses himself. “Israel ate and was filled, and the darling grew fat and frisky.” When brute animals feed from a full manger, they grow plump and become more obstinate and hard to hold in check; they endure neither the yoke, the reins, nor the hand of the charioteer. Just so, the Jewish people were driven by their drunkenness and plumpness to ultimate evil. They kicked about and failed to accept the yoke of Christ. And they failed to pull the plow of his teaching. Another prophet hinted at this when he said, “Israel is as obstinate as a stubborn heifer.” And still another called the Jews “an untamed calf.” .