Saṃhāra-krama (The Sequence of Cosmic Dissolution) — Yājñavalkya’s Discourse
यथा कश्रिद् वन॑ घोरं बहुसर्पसरीसूपम् । श्वभ्रवत् तोयहीनं च दुर्गमें बहुकण्टकम्,जैसे कोई-कोई बिरला नवयुवक ही अनेकानेक सर्पों तथा विच्छू आदिसे भरे हुए गड़्ढ़ों और बहुत-से काँटोंवाले, जलशून्य, दुर्गम एवं घोर वनमें सकुशल यात्रा कर सकता है तथा जहाँ भोजन मिलना असम्भव है, जिसमें प्रायः जंगल-ही-जंगल पड़ता है, जहाँके वृक्ष दावानलसे जलकर भस्म हो गये हैं तथा जो चोर-डाकुओंसे भरा हुआ है, ऐसे मार्गको सकुशल तै कर सकता है; उसी प्रकार योगमार्गका आश्रय लेकर कोई बिरला ही द्विज उसपर कुशलपूर्वक चल पाता है, क्योंकि वह बहुत-से दोषों (कठिनाइयों)-से भरा हुआ बताया गया है
yathā kaścid vanaṁ ghoraṁ bahu-sarpa-sarīsṛpam | śvabhravat toyahīnaṁ ca durgamaṁ bahu-kaṇṭakam ||
Bhishma said: Just as only some rare person can safely pass through a terrifying forest—like a waterless ravine—infested with many snakes and creeping creatures, hard to traverse and full of thorns, where sustenance is scarcely found and danger abounds; so too, only a rare twice-born, taking refuge in the path of Yoga, is able to proceed on it successfully, for that path is said to be filled with many faults and hardships.
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.