八識規矩補註 2.17

2.17

This means that when this consciousness transforms into the uncontaminated at the initial heart of the first bhūmi, the wisdom into which the corresponding mental factors are transformed also becomes uncontaminated, because the sixth consciousness enters the contemplation of dual emptiness. When the sixth enters the contemplation of the emptiness of persons, it hinders this seventh's ātmagrāha from arising, but dharmagrāha remains constant; hence the Treatise says: "When manas with only singular grasping abides in the seed state, the wisdom of equality does not manifest." When the sixth enters the contemplation of both emptinesses of persons and dharmas, it hinders this seventh's two grasps of self and dharmas from arising; hence the Treatise says: "When manas with dual grasping returns to the seed state, the wisdom of equality only then manifests." This means that the seventh consciousness lacks the power to sever afflictions and grasping, relying entirely on the sixth consciousness. Hence a verse says: "The differentiated two hindrances are absent at the Utmost Joy; the innate [hindrances] of the sixth and seventh are eliminated bhūmi by bhūmi; the seventh on the path of cultivation eliminates seeds and manifestations; after the vajra-path, all are completely absent." Therefore, the seventh becoming uncontaminated is entirely due to the superiority of the sixth in severing afflictions and realizing the principle.