This space between heaven and earth, and all the directions, are filled by you alone. Seeing this wondrous, terrifying form of yours, O great-souled one, the three worlds tremble in distress.
Explanation
Arjuna, having asked to see Krishna's universal form, now describes it in awe and fear. The form fills the whole space between heaven and earth and every direction, and the three worlds (lokatraya), usually understood as heaven, earth and the netherworld, shake at the sight. Arjuna's own trembling is often read as being voiced through this description of the worlds.