Mahabharata 12.105.18

आत्मनोऽध्रुवतां पश्यंस्तांस्त्वं किमनुशोचसिबुद्ध्या चैवानुबुध्यस्व ध्रुवं हि न भविष्यसि

ātmano'dhruvatāṃ paśyaṃstāṃstvaṃ kimanuśocasibuddhyā caivānubudhyasva dhruvaṃ hi na bhaviṣyasi

Our plain-language meaning of this verse is waiting for scholar review.