Chāndogya Upaniṣad 7.12.2

7.12.2

sa ya ākāśaṃ brahmety upāste \
ākāśavato vai sa lokān prakāśavato 'saṃbādhān urugāyavato 'bhisidhyati \
yāvad ākāśasya gataṃ tatrāsya yathākāmacāro bhavati ya ākāśaṃ brahmety upāste \
asti bhagava ākāśād bhūya iti \
ākāśad vāva bhūyo 'stīti \
tan me bhagavān bravītv iti \\712.2\

2. He who reverences Space as Brahma—he, verily, attains spacious, gleaming, unconfined, wide-extending worlds. As far as Space goes, so far he has unlimited freedom, he who reverences Space as Brahma.’

‘Is there, Sir, more than Space?’

‘There is, assuredly, more than Space.’

‘Do you, Sir, tell me it.’