तं दुर्दर्शं गूढमनुप्रविष्टं गुहाहितं गह्वरेष्ठं पुराणम् ।अध्यात्मयोगाधिगमेन देवं मत्वा धीरो हर्षशोकौ जहाति ॥ १२ ॥
In plain words
Recognizing that hard-to-see, hidden, deeply-entered, cave-dwelling, depth-abiding, ancient one -- that Self -- as divine, through the attainment of the discipline that turns toward it inwardly, the steady one abandons both joy and grief.