起信論疏筆削記 10.27

10.27

今於疏外別助一解：言心與無明俱無形相者，此約真妄各住自位時說也。舉此義者，要顯真妄之相不相離故，以真本無形相，約染心以說其相。無明亦無形相，還指染心以為其相。斯則住自位時雖無形相，而真妄和合共現染相。以此染法亦是真如相，亦是無明相，故云不相捨離。如父母共生一子，此子亦是父之子，亦是母之兒也。

Now, outside the commentary, I offer an additional explanation: when it is said that the mind and ignorance both lack visible shape, this is spoken in terms of when the true and the false each abide in their own positions. Bringing up this meaning is precisely to reveal that the marks of the true and the false are not separated from each other, because the true fundamentally lacks visible shape, and its marks are spoken of in relation to the defiled mind. Ignorance also lacks visible shape, and points back to the defiled mind as its mark. Thus, when abiding in their own positions, although they lack visible shape, the true and the false combine to jointly manifest defiled marks. Because this defiled dharma is both a mark of tathatā and a mark of ignorance, it is said that they are not separated from one another. It is like a father and mother jointly giving birth to a single child; this child is both the father's child and the mother's child.