The Mukhya Upaniṣads

Kauṣītaki · Adhyāya 4 · Kauṣītaki 4.1

Passage 14

स होवाच बालाकिर्य एवैष शारीरः पुरुषस्तमेवाहमुपास इति तं होवाचाजातशत्रुर्मा मैतस्मिन्समवादयिष्ठाः प्रजापतिरिति वा अहमेतमुपास इति स यो हैतमेवमुपास्ते प्रजायते प्रजया पशुभिः ॥ १४ ॥

In plain words

Bālāki said, "The person who is in the body — him indeed I worship." Ajātaśatru said to him, "Do not draw me into talk about him. I worship him as Prajāpati." He who worships him thus is made fruitful with offspring and cattle.