Chuang Tze was resting under the shade of a large gnarled tree, when Hui sneered to him, "Your teachings are completely useless, like this tree: none of its limbs can yield a straight plank, nothing can be carved from its knotted grain."
Chuang Tze chuckled, "Useless? Yes. No axe or saw will fell this tree. Its shade and fruits endure in the wasteland, provide refuge for the tired and thirsty. If your teachings are so useful, I'd be worried if I were you!"