The children of a rich father were so enchanted by all of their toys, that they did not even notice when their house caught on fire. The father, despairing for their safety, lured the children out of the burning house by calling to them with the news that he had gifts of three kinds of carts— goat carts, deer carts, and ox carts—for them to play with outside the gate.
This promise broke the spell, and the children ran out to their father to receive the gifts. When the children escaped the burning house, the father gave them a great cart yoked by white oxen, which is more than they had hoped for.
In the same way, buddhas use expedient means to make living beings realize the Buddha’s wisdom. Even as buddhas discriminate and explain the three vehicles by which śrāvakas, pratyekabuddhas, and bodhisattvas should transcend the triple world, buddhas know that in reality there is only the One Buddha Vehicle, which is the real wisdom of zazen.