Srimad-Bhagavatam: Canto 2 - Chapter 1 - Verse 35

Sanskrit:

स एव पुरुषस्तस्मादण्डं निर्भिद्य निर्गत: ।सहस्रोर्वङ्‌घ्रिबाह्वक्ष: सहस्राननशीर्षवान् ॥ ३५ ॥

ITRANS:

sa eva puruṣas tasmādaṇḍaṁ nirbhidya nirgataḥsahasrorv-aṅghri-bāhv-akṣaḥsahasrānana-śīrṣavān

Translation:

The Lord [Mahā-Viṣṇu], although lying in the Causal Ocean, came out of it, and dividing Himself as Hiraṇyagarbha, He entered into each universe and assumed the virāṭ-rūpa, with thousands of legs, arms, mouths, heads, etc.

Purport:

The expansions of the planetary systems within each and every universe are situated in the different parts of the virāṭ-rūpa (universal form) of the Lord, and they are described as follows.