The awareness of mortals falls short. As long as they're attached to appearances, they're unaware that their minds are empty. And by mistakenly clinging to the appearance of things they lose the Way.
BodhidharmaBut people of the deepest understanding look within, distracted by nothing. Since a clear mind is the Buddha, they attain the understanding of a Buddha without using the mind.
BodhidharmaLeaving behind the false, return to the true: make no discriminations between self and others. In contemplation, one's mind should be stable and unmoving, like a wall.
Bodhidharma