Ālayavijñāna is a formless and immaterial mind-dharma

Ālayavijñāna is a formless, immaterial mind-dharma (citta-dharma), not material form (rūpa). Therefore, because one cannot find the physical appearance of ālayavijñāna in material form, one says that the eyes do not contain ālayavijñāna; if they did, one would be able to see ālayavijñāna. Nor does the physical body contain ālayavijñāna; if the body contained ālayavijñāna, one would not only be able to see it, but also be able to feel it. In reality, we can neither see ālayavijñāna nor feel it; we cannot smell it, cannot hear it, and cannot think of it. Only through investigating Chan (cān chán) can one realize the function of ālayavijñāna.