瑜伽論記 8.158

8.158

第三明無所得行趣入空行，景云：觀心相續離第二法唯有其心，心外無我故名為空，即蘊我無名為無我。

Third, explaining the entry into the aspect of emptiness through the aspect of non-apprehension: Jing says: "One contemplates the continuum of the mind as being free from a second factor, with only the mind existing. Because there is no self outside of the mind, it is called empty; the non-existence of a self in the aggregates is called non-self."