Saṃhāra-krama (The Sequence of Cosmic Dissolution) — Yājñavalkya’s Discourse
सुस्थेयं क्षुधधारासु निशितासु महीपते । धारणासु तु योगस्य दुःस्थेयमकृतात्मभि:
su-stheyaṁ kṣudhā-dhārāsu niśitāsu mahīpate | dhāraṇāsu tu yogasya duḥstheyam akṛtātmabhiḥ pṛthvīpate ||
Bhīṣma dit : «Ô roi, on peut, avec aisance, se tenir debout même sur le tranchant aigu d’une lame ; mais pour ceux dont l’être intérieur n’est ni purifié ni discipliné, demeurer stable dans les pratiques de concentration yogique (dhāraṇā) est d’une difficulté extrême.»
भीष्म उवाच
External hardships can be borne, but true steadiness in yogic concentration demands an inwardly purified, disciplined mind; without self-mastery (kṛtātman), dhāraṇā becomes extremely difficult.
In the Śānti Parva’s instruction to the king, Bhīṣma emphasizes the rigor of inner spiritual practice, using the razor-edge image to contrast physical endurance with the greater challenge of mental and ethical self-discipline required for yoga.