大乘義章 2.8

2.8

次就理法以說三門。如《成實》說，理體寂故名之為空，是空理中無諸相故說為無相，無願求心說為無願。又《大智論》亦同此說，故彼論言「摩訶衍中三脫是一，以行因緣故說三門。觀諸法空說為空門；於此空中不取於相，是時空門轉名無相；於無相中更無所作，是時無相轉名無作。以同體故。若人入空終不起相亦無所作，乃至入彼無作門中亦知空義不取於相，但隨人別觀入不同故立三門。」

Next, speaking of the three gates in reference to the dharma of principle. As stated in the Tattvasiddhi, because the essence of principle is quiescent, it is called emptiness; within this principle of emptiness, because there are no signs, it is spoken of as signlessness; the absence of a mind of wishing and seeking is spoken of as wishlessness. Furthermore, the Mahāprajñāpāramitopadeśa also agrees with this statement; hence that treatise says: "In the Mahāyāna, the three liberations are one, but by reason of practice, three gates are spoken of. Contemplating the emptiness of all dharmas is spoken of as the gate of emptiness; when, within this emptiness, one does not seize upon signs, at that time the gate of emptiness shifts to being named signlessness; when, within signlessness, there is no further action to be done, at that time signlessness shifts to being named actionlessness. This is because they share the same essence. If a person enters emptiness, they will ultimately not give rise to signs nor engage in action; even when entering that gate of actionlessness, they also understand the meaning of emptiness and do not seize upon signs; it is merely that according to the individual, their contemplation and entry differ, so three gates are established."