維摩經略疏垂裕記 1.126

1.126

二、「權生方便願來」者，但在菩薩。小從得記，義亦同之。生方便土，未破無明，欲化眾生，須假願牽，未能任運，故使應生唯約二土。

Second, regarding 'expedient birth through provisional manifestation by the power of vows,' this applies only to bodhisattvas. As for the lesser [vehicle adherents], from the point they receive prophecy, the principle is also the same. When born into the land of expedience, because they have not yet broken ignorance, if they wish to convert sentient beings, they must rely on the traction of vows; unable to act spontaneously, their responsive birth is therefore restricted only to the two lands.