Saṃhāra-krama (The Sequence of Cosmic Dissolution) — Yājñavalkya’s Discourse
यथा कश्रिद् वन॑ घोरं बहुसर्पसरीसूपम् । श्वभ्रवत् तोयहीनं च दुर्गमें बहुकण्टकम्
yathā kaścid vanaṁ ghoraṁ bahu-sarpa-sarīsṛpam | śvabhravat toyahīnaṁ ca durgamaṁ bahu-kaṇṭakam ||
यथा कश्चिद् वनं घोरं बहुसर्पसरीसृपम् । श्वभ्रवत् तोयहीनं च दुर्गमं बहुकण्टकम् ॥ अल्पाहारं बहुत्रासं दावदग्धमहीरुहम् । तस्कराकीर्णपन्थानं क्षेमेणाभिपतेद् युवा ॥ तथा योगपथं श्रित्य कश्चिदेव द्विजो नरः । क्षेमेण व्रजते तत्र बहुदोषो हि स स्मृतः ॥
भीष्म उवाच
The verse teaches that the yogic path is intrinsically difficult and perilous—like crossing a deadly, thorny, waterless forest—and therefore only a rare, well-prepared practitioner can proceed safely; it calls for vigilance, endurance, and freedom from common pitfalls.
In Shanti Parva, Bhishma instructs Yudhishthira on higher dharma and spiritual disciplines. Here he uses a vivid simile of a dangerous forest journey to explain why progress on the path of Yoga is uncommon and requires exceptional steadiness.