द्यावापृथिव्योरिदमन्तरं हि व्याप्तं त्वयैकेन दिशश्च सर्वाः ।
दृष्ट्वाद्भुतं रूपमुग्रं तवेदंलोकत्रयं प्रव्यथितं महात्मन् ॥
Transliteration
dyāvāpṛthivyor idam antaraṃ hi vyāptaṃ tvayaikena diśaśca sarvāḥ |
dṛṣṭvādbhutaṃ rūpam idaṃ tavograṃ loka trayaṃ pravyathitaṃ mahātman || 20 ||
Translation
Space in all quarters of skies and earth is filled by you alone. Beholding Your spectacular and awesome form, O Great soul, the three worlds are trembling.
Purport
Arjuna further describes what he witnessed. Every space in-universe is filled with Bhagwan Krishna alone. He is everywhere. This spectacular form, never seen before all deities and living beings on higher planets, are trembling. Here point to be noted that no human except Veda Vyasa, Sanjaya and Arjuna could have seen this universal form of Bhagawan Shri Krishna. Higher beings in otherLokas, like Deva Loka, Bramha Loka, etc could see the universal form. Three worlds cover all the possible planets in-universe. Three worlds trembling here signifies anybody who could see the universal form of Shri Krishna is overwhelmed, so much that trembling, unable to grasp the form.