大乘起信論裂網疏 3.112

3.112

粗中之細，即不斷相應染、分別智相應染。細中之粗，即現色不相應染、見心不相應染。菩薩，謂淨心地已上。細中之細，即根本業不相應染，唯有佛智乃能照其源也。

"The subtlest among the coarse" refers to the continuous associated defilement and the defilement associated with discriminative intellect. "The coarsest among the subtle" refers to the defilement non-associated with manifest form and the defilement non-associated with the seeing mind. "Bodhisattvas" refers to those from the stage of the pure mind and above. "The subtlest among the subtle" is the fundamental karma non-associated defilement, the source of which only the Buddha's wisdom can illuminate.