瑜伽論記 7.464

7.464

尋思障者，謂欲恚害等尋思，知障過患，謂此障有故於其四種障在身時未證不證已得退失，乃至生諸惡趣，名知障過。

The 'obstacle of discursive thought' refers to discursive thoughts of sensual desire, malice, harm, and the like. 'Knowing the faults of the obstacles' means that because these obstacles exist, when the four kinds of obstacles are present in the body, one does not attain what has not been attained, loses what has already been attained, and even falls into the evil destinies; this is called knowing the faults of the obstacles.