大毘盧遮那成佛經疏 2.77

2.77

第四十八「云何迷心？謂所執異所思異」者，如人迷故，意欲向東而更向西。此人心亦如是，意欲學不淨觀，而反取淨相，自謂我今修不淨觀。若修無常無我時，反行常我倒中，謂我今修無常無我。由心散亂，故使然也。當念專一其心，審諦安詳無倒觀察，是彼對治。

As for the forty-eighth, “What is the confused mind? It refers to that which is grasped being different from that which is thought”: Just as a person, being confused, intends to go east but instead turns west, this person's mind is also like this. Intending to learn the contemplation of impurity, they instead grasp at marks of purity, telling themselves, “I am now cultivating the contemplation of impurity.” When cultivating impermanence and non-self, they instead practice within the inversions of permanence and self, saying, “I am now cultivating impermanence and non-self.” Because the mind is distracted, it causes this to happen. One should contemplate focusing the mind, observing carefully, serenely, and without inversion—this is its antidote.