The Mukhya Upaniṣads

Aitareya · Adhyāya 1 · Khaṇḍa 1 · The Waking of the Self into Worlds and Person

Passage 1

ॐ आत्मा वा इदमेक एवाग्र आसीत् ।नान्यत्किञ्चन मिषत् ।स ईक्षत लोकान्नु सृजा इति ॥ १ ॥

In plain words

Om. In the beginning, this was the Self alone — nothing else whatsoever stirred or perceived. He thought: 'Let me now create the worlds.'