八識規矩補註 2.19

2.19

This means that prior to the eighth bhūmi, this consciousness's dharmagrāha is still constant, while ātmagrāha is intermittent, because the sixth is not constantly in the contemplation of dual emptiness; upon reaching this Immovable bhūmi, ātmagrāha is perpetually suppressed, and dharmagrāha arises intermittently, because the sixth is constantly in the contemplation of the emptiness of persons. Why are its seeds not severed? Because they do not obstruct the cause, because they are of the lowest grade, because they arise spontaneously, because their essence is subtle, and because they are merely nivṛta.