Having understood that the senses are distinct (from the Âtman), and that their rising and setting (their waking and sleeping) belongs to them in their distinct existence (and not to the Âtman), a wise man grieves no more.

In plain words: A wise person sees that the senses are separate from the true Self. Waking and sleeping belong to the senses, not to the Self. Knowing this, the wise person grieves no more.