法華論疏 2.553

2.553

以因果行觀不同故者，釋二乘非一乘體義。約二乘因果觀行，故非平等法身。七方便為因，真聖位為果。行者，二乘所行四諦等法。觀者，人無我觀。以此四義竝不同大乘，是故二乘非平等法身之體。問：云何以平等法身為一乘體？答：乘有三種，一性乘、二隨乘、三乘得。性乘即是真如法身；要由有真如法身，然後修於萬行，稱曰乘隨；證得佛果名為乘得。以性乘是根本，故說為一乘體。

"Because their causes, fruits, practices, and contemplations are not the same" explains the meaning of why the two vehicles are not the essence of the One Vehicle. Approached in terms of the causes, fruits, contemplations, and practices of the two vehicles, they are therefore not the equal dharmakāya. The seven skillful means are the cause; the stage of true holiness is the fruit. "Practices" refers to the dharmas such as the Four Truths practiced by the two vehicles. "Contemplations" refers to the contemplation of the selflessness of persons. Because these four meanings are all unlike the Mahāyāna, the two vehicles are therefore not the essence of the equal dharmakāya. Question: Why is the equal dharmakāya taken as the essence of the One Vehicle? Answer: There are three kinds of vehicle: first, the vehicle of nature; second, the vehicle of compliance; third, the vehicle of attainment. The vehicle of nature is precisely the dharmakāya of thusness; only by possessing the dharmakāya of thusness does one then cultivate the myriad practices, which is called the vehicle of compliance; realizing and attaining the Buddha fruit is called the vehicle of attainment. Because the vehicle of nature is the fundamental root, it is expounded as the essence of the One Vehicle.