Bhagavad Gita 11.13

तत्रैकस्थं जगत्कृत्स्नं प्रविभक्तमनेकधा।
अपश्यद्देवदेवस्य शरीरे पाण्डवस्तदा।।11.13।।

Tatraikastham jagatkritsnam pravibhaktamanekadha
Apashyaddevadevasya sharire pandavastada

Simple meaning, written by AIIn that single form Arjuna saw the whole universe, divided into many parts, within the body of the Supreme God.