法華經義記 3.13

3.13

The questioner says: “If the liberation of the three houses is of one equal grade, there ought not to be distinctions in their receiving the three carts.” The interpreter says: “The reason the liberation of the three houses is of one equal grade is that all alike take the unconditioned [state] wherein the causes and effects of the three realms are exhausted; since the unconditioned is not distinct, all are therefore designated ‘one liberation.’ As for why there is the parable of the three carts and differences in superior and inferior conveyed causes, this is based on their power and function having shorter and longer reaches. The śrāvakas exhausting the primary fetters of the three realms is likened to the goat cart; the pratyekabuddhas encroaching upon a small portion of residual propensities is likened to the deer cart; and the bodhisattvas exhausting the residual propensities altogether is likened to the ox cart.”