大乘入道次第 1.53

1.53

又此位中，雙修安立、非安立觀。即四諦等，名為安立。二空觀等，名非安立。此乃略明加行位中別修行相。

Furthermore, within this stage, one doubly cultivates the established (vyavasthāna) and unestablished (avyavasthāna) contemplations. That is, the four truths and so forth are called the established; the contemplation of the two emptinesses and so forth are called the unestablished. This briefly explains the distinct characteristics of practice in the stage of preparatory application.