瑜伽論記 1.467

1.467

自下第三明空劫中，乃至餘影亦不可得，此雖無文，亦同小乘有空界色。言無影者，以無質故，非無逈色。又如經說：空劫之時，猶如闇穴。故知有闇色。

From here below, the third [part] explains the kalpa of emptiness. 'Up to not even a shadow being found'—although there is no text for this, it also agrees with the Hīnayāna that there is matter of the space element. The statement that there is no shadow is because there is no physical substance, not that there is no distal form. Furthermore, as the sūtra says: 'At the time of the kalpa of emptiness, it is like a dark cave.' Therefore, we know there is dark form.