यतश्चोदेति सूर्योऽस्तं यत्र च गच्छति । तं देवाः सर्वेऽर्पितास्तदु नात्येति कश्चन । एतद्वै तत् ॥

ॐ

English Commentary

Whence the sun rises and whither it goes to set, in whom all the devas are contained and whom none can ever pass beyond- This, verily, is That. 

ॐ

English Commentary

Moreover, that prâna from which the sun rises and that where alone the sun every day sets, that prana. i.e., the Adhidaiva and the Adhyâtma aspect of Atman as the gods and speech, etc., as the senses enter into, while they last, as spokes in a wheel. Even he is certainly Brahman. That is this Brahman, the âtman of all. None certainly passes beyond that] none ceasing to be of the nature of that becomes other than that. This verily is that.

Sri Shankaracharya