Verse 5.18.1

तान्होवाचैते वै खलु यूयं पृथगिवेममात्मानं वैश्वानरं विद्वांसोऽन्नमत्थ यस्त्वेतमेवं प्रादेशमात्रमभिविमानमात्मानं वैश्वानरमुपास्ते स सर्वेषु लोकेषु सर्वेषु भूतेषु सर्वेष्वात्मस्वन्नमत्ति ॥ ५.१८.१ ॥

tānhovācaite vai khalu yūyaṃ pṛthagivemamātmānaṃ vaiśvānaraṃ vidvāṃso'nnamattha yastvetamevaṃ prādeśamātramabhivimānamātmānaṃ vaiśvānaramupāste sa sarveṣu lokeṣu sarveṣu bhūteṣu sarveṣvātmasvannamatti || 5.18.1 ||

1. The king said to the brāhmins: ‘Those of you who are here meditate on the Vaiśvānara Self only in part. [That is why when you eat you think you are eating separately.] He who worships the Self as all-pervasive and infinite, enjoys eating through whoever eats in the worlds, through all beings, and through all selves.

Word-for-word explanation:

Tān, to them [the brāhmins]; ha uvāca, [the king] said; ete yūyam vai khalu, those of you here; imam vaiśvānaram ātmānam vidvāṃsaḥ, have known this [undivided] Vaiśvānara Ātman; pṛthak iva, only in part [and as separate in each individual]; annam attha, [and that is why] you eat food [thinking you are eating separately; yaḥ tu, but he who; etam evam vaiśvānaram ātmānam upāste, worships this Vaiśvānara Ātman thus; prādeśamātram, as all-pervasive [i.e., as covering the various worlds]; abhivimānam, [and] infinite; saḥ, he; sarveṣu lokeṣu, in all the worlds; sarveṣu bhūteṣu, in all beings; sarveṣu ātmasu, in all selves; annam atti, eats food.

Commentary:

Prādeśamātra means one who covers all the worlds, from heaven to the earth—including everything and every being. Abhivimāna means infinite, beyond measure.

Here the principle is that if you worship God as finite, you remain finite; if you worship him as infinite, you become infinite. Another principle suggested is that you are one with all. You are happy if all are happy. You cannot expect anything for yourself to the exclusion of others.

Yet another principle is to regard your body as the place of an Agnihotra sacrifice, and the food you eat as the oblation.

The six scholars mentioned here worshipped the Vaiśvānara Ātman in part—as either heaven, the sun, air, space, water, or the earth. Aśvapati told them their worship was not complete. They should include their own self also as the Vaiśvānara Ātman. In fact, they should realize that there is but one Self and that Self is in everything and in every being.