瑜伽師地論略纂 8.9

8.9

論解法教久住中云「當知說彼勝義正法作證道理」等者，此意明正法五百內，由有正法作證。

Where the treatise explains the long endurance of the Dharma teaching, saying, "One should know that this speaks of the principles of realizing that supreme true Dharma," and so forth: this meaning clarifies that within the five hundred years of the true Dharma, it is due to there being realization of the true Dharma.