Shloka 20
सत्य–अनृत, प्रकाश–तमस्, स्वर्ग–नरक विवेचनम्
Truth and Untruth as Light and Darkness; Svarga and Naraka as Ethical Consequences
आकाशका ऊपरी भाग उनका सिर है, पृथ्वी पैर है और दिशाएँ भुजाएँ हैं। वे अचिन्त्यस्वरूप ब्रह्मा सिद्ध पुरुषोंके लिये भी दुर्विज्ञेय हैं, इसमें संशय नहीं है ।।
ākāśa-kā uparī bhāga unakā śira hai, pṛthvī paira hai aura diśāeṁ bhujāeṁ haiṁ. te acintya-svarūpa brahmā siddha-puruṣoṁ ke liye bhī durvijñeya haiṁ, ismeṁ saṁśaya nahīṁ hai. sa eṣa bhagavān viṣṇur ananta iti viśrutaḥ; sarva-bhūtātma-bhūta-stho durvijñeyo 'kṛtātmabhiḥ.
毗湿摩说道：“苍穹上际为其首，大地为其足，诸方为其臂。其形相不可思议；即便梵天与诸成就圣者亦难以了悟——对此毫无疑问。彼即是世尊毗湿奴，号称阿难多（无尽者），作为内在之我，安住于一切众生心中。若其内性未炼、心不清净，欲如实知其真相，实为极难。”
भीष्म उवाच
Educational Q&A
The verse teaches that the Supreme (identified as Viṣṇu/Ananta) pervades the cosmos and dwells within every being as the inner Self, yet remains ultimately inconceivable; genuine understanding requires inner purification and disciplined character.
In the Śānti Parva’s instruction to Yudhiṣṭhira, Bhīṣma continues a theological exposition, describing the Lord’s cosmic pervasion and emphasizing that even exalted beings struggle to grasp Him, while the impure-minded find true knowledge of Him especially difficult.