देव–विष्णु–संवादः । कालेयगणस्य समुद्राश्रयः । अगस्त्योपसर्पणम्
Devas and Viṣṇu on the Kāleyas; Approach to Agastya
ज्ञात्वा बलस्थं त्रिदशाधिपं तु ननाद वृत्रो महतो निनादान् | तस्य प्रणादेन धरा दिशश्व खं द्यौर्नगाश्नापि चचाल सर्वम्,देवताओंसहित श्रीविष्णु तथा महाभाग महर्षियोंके तेजसे परिपूर्ण हो देवराज इन्द्र अत्यन्त बलशाली हो गये। देवेश्वर इन्द्रको बलसे सम्पन्न जान वृत्रासुरने बड़ी विकट गर्जना की। उसके सिंहनादसे भूलोक, सम्पूर्ण दिशाएँ, आकाश, स्वर्गलोक तथा पर्वत सब-के-सब काँप उठे
jñātvā balasthaṃ tridaśādhipaṃ tu nanāda vṛtro mahato ninādān | tasya praṇādena dharā diśaś ca khaṃ dyaur nagāś cāpi cacāla sarvam ||
Seeing that the lord of the Thirty Gods—Indra—had become firmly established in strength, Vṛtra let out a tremendous, terrifying roar. By the force of that lion-like cry, the earth, the directions, the sky, the heavenly realm, and even the mountains all shook.
लोगश उवाच
Power in the epic is not merely physical; it is cosmic and moral. When divine authority becomes strengthened, forces opposed to that order often respond with intimidation and upheaval. The verse highlights how inner dispositions—defiance, pride, or resistance—can manifest as disruptive force, while true stability is associated with alignment to cosmic order.
Indra, empowered (in the surrounding context, through divine and sage-like radiance/aid), stands strong. Recognizing this, Vṛtra responds with a massive roar so intense that it makes the earth, the directions, the sky, heaven, and mountains tremble—an omen-like display of the impending clash.