अधिभूतं क्षरो भावः पुरुषश्चाधिदैवतम्।अधियज्ञोऽहमेवात्र देहे देहभृतां वर॥
adhibhūtaṃ kṣaro bhāvaḥ puruṣaś cādhidaivatamadhiyajño ’ham evātra dehe deha-bhṛtāṃ vara
Word by word
The verse says
The ground of matter is the perishable nature. The ground of the gods is the cosmic person. And the ground of sacrifice is myself, here, in this body, best of the embodied.
In plain words
Two more answers, and then the one that lands somewhere unexpected.
Where is the ground of sacrifice, the thing that makes any offering work? Not in a heaven, not in a rite.
Atra dehe — here, in this body. The one you are currently sitting in.
Where you've felt this · in community
You keep meaning to go up to the old fort on the hill outside town. Every visitor you have gets taken there, and they come back saying it was worth it. You have lived at the bottom of that hill for eleven years and you have been up twice, both times with somebody else's relatives.
Going deeper
Locating the divine inside the body is the quiet revolution in this verse, and it is stated as though it were obvious.
Adhiyajña means the one who stands behind sacrifice — the reason any offering reaches anywhere. In the older picture that reason lived somewhere else, and ritual was the pipework connecting here to there. Krishna says it is already here, in the body of the person asking.
So the site of practice is not somewhere you travel to. It is where you are sitting, which sounds encouraging until you notice it also removes every excuse. You cannot be waiting for better conditions. There are no better conditions coming.
What this changes is where you look. If nothing has to be reached, then attention, not distance, is the whole of the problem.