瑜伽師地論略纂 8.171

8.171

論解壞道沙門中云「由彼破壞最初所有正道根本」等者，此中意，謂戒為正道根本，今破戒故，名壞道根。

In explaining the śramaṇa who corrupts the path, the treatise says: "Because they destroy what was initially the root of the right path," and so forth. The meaning here is that moral discipline is the root of the right path; now, by breaking moral discipline, it is called destroying the root of the path.