Kaṭha Upaniṣad 5.8-2.p15

5.8-2.p15

yadvā - parasya brahmaṇaḥ sarvabhūteṣu antarbahiśca vyāptiṃ dṛṣṭāntapūrvakam avagamayati - agniḥ iti | agniḥ iha tejaḥ | na hi agninā avyāptaḥ kaściddeśaḥ | sa hi sarvatra sūkṣmarūpeṇa sannihitaḥ | iyāṃśca viśeṣaḥ; sthūleṣu jalādisakalabhūteṣu antarvyāpyāsti | yattu sūkṣmaṃ tatra tu - bahireva kevalaṃ vyāptaḥ | tadevam antarbahiśca vyāpya vartamāno'pi aviṣama eva yathā ayam; tathā sarvabhūtāntarātmā antarbahiśca aviṣama eva vyāpya vartata ityāśayena āha - agniḥ yathā bhuvanaṃ praviṣṭaḥ bahiśca ekaḥ tathā sarvabhūtāntarātmā iti | paraṃbrahma antaryāmitayā sūkṣmarūpeṇa sarvabhūteṣu antarbahiśca vyāpya vartamānam, bahirantaḥ pradeśarūpa upādhibhede'pi svayamaviṣamameveti bhāvaḥ | antaḥ praveśe viśeṣamāha -