चित्ते चित्तदशाहीने या स्थितिः क्षीणचेतसाम् ।सोच्यते शान्तकलना जाग्रत्येव सुषुप्तता
In plain words
When citta is empty of the very state of being citta — the condition of those whose minds have worn thin — that is called śānta-kalanā, kalanā fallen silent: it is deep sleep itself, in the midst of waking.