法界次第初門 2.44

2.44

四、虛空處背捨。若滅根本四禪色及三背捨、四勝處、八一切處中色，一心緣無邊虛空而入定，即觀此定依陰、入、界，故有無常、苦、空、無我，虛誑不實，心生厭背而不受著，深入一向不迴，是為虛空處背捨。

Fourth, the liberation of the sphere of space. If, having annihilated the form of the fundamental four dhyānas and the forms in the three liberations, the four bases of mastery, and the eight kṛtsnāyatanas, one single-mindedly takes boundless space as object and enters concentration, one then contemplates that this concentration relies on the skandhas, āyatanas, and dhātus, and therefore is impermanent, suffering, empty, non-self, deceptive, and unreal; generating a mind of revulsion and turning away, one does not cling to or attach to it, but enters deeply and single-mindedly without turning back—this is the liberation of the sphere of space.