18.21

पृथक्त्वेन तु यज्ज्ञानं
नानाभावान्पृथग्विधान् ।
वेत्ति सर्वेषु भूतेषु
तज्ज्ञानं विद्धि राजसम् ॥

pṛthaktvena tu yaj jñānaṃ nānābhāvān pṛthagvidhān
vetti sarveṣu bhūteṣu taj jñānaṃ viddhi rājasam

Kṛṣṇa (कृष्ण) is still speaking, to Arjuna (अर्जुन). This is the second knowledge, the one of rajas (रजस्).

The verse

That knowledge which knows, by separateness, the various beings of different kinds in all beings, know as rājasa (राजस).

नेपालीमा

जुन ज्ञानले सबै प्राणीमा भिन्न भिन्न प्रकारका अनेक भावलाई छुट्टै छुट्टै चिन्छ, त्यसलाई राजस भनी बुझ।

Where it sits

18.20 saw one imperishable being in all beings, and this knowledge sees many, of separate kinds, in that same place, sarveṣu bhūteṣu (सर्वेषु भूतेषु). 18.22 is the third, and it is smaller.

Split: पृथक्त्वेन + तु + यत् + ज्ञानम् + नाना-भावान् + पृथक्-विधान् + वेत्ति + सर्वेषु + भूतेषु + तत् + ज्ञानम् + विद्धि + राजसम्

pṛthaktvena + tu + yat + jñānam + nānā-bhāvān + pṛthak-vidhān + vetti + sarveṣu + bhūteṣu + tat + jñānam + viddhi + rājasam

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
पृथक्त्वेनpṛthaktvenainstrumental singular of pṛthaktva (पृथक्त्व)by separateness. By the fact of being apart.
तुtuindeclinablebut.
यत्yatnominative singular neuterwhich.
ज्ञानम्jñānamnominative singularknowledge.
नाना-भावान्nānā-bhāvānaccusative pluralthe various beings. Many states.
पृथक्-विधान्pṛthag-vidhānaccusative pluralof different kinds. Agrees with nānā-bhāvān (नाना-भावान्).
वेत्तिvettipresent, 3rd singular of vid (विद्)it knows.
सर्वेषुsarveṣulocative pluralin all.
भूतेषुbhūteṣulocative pluralin beings.
तत्tataccusative singular neuterthat.
ज्ञानम्jñānamaccusative singularknowledge.
विद्धिviddhiimperative, 2nd singularknow.
राजसम्rājasamaccusative singular neuterof rajas (रजस्).

The phrases

pṛthaktvena tu yat jñānam (पृथक्त्वेन तु यत् ज्ञानम्) is knowledge whose way is separateness. yat jñānam (यत् ज्ञानम्) is yaj jñānam (यज्ज्ञानम्), and before nānā (नाना) the anusvara stands: yaj jñānaṃ (यज्ज्ञानं).

नाना-भावान् पृथक्-विधान् वेत्ति nānā-bhāvān pṛthag-vidhān vetti is what it knows: many beings, of different kinds. pṛthak-vidhān (पृथक्-विधान्) is recited pṛthagvidhān (पृथग्विधान्). The line keeps the n (न्) of bhāvān (भावान्) in front of p (प्), as the source prints it: nānābhāvān pṛthagvidhān (नानाभावान्पृथग्विधान्).

sarveṣu bhūteṣu (सर्वेषु भूतेषु) is where: in all beings. tat jñānam viddhi rājasam (तत् ज्ञानम् विद्धि राजसम्) is the same command as 18.20, with the other name. Know that knowledge as rājasa (राजस).

Sanskrit in this line

pṛthaktvena (पृथक्त्वेन) is instrumental, "by separateness." It says how this knowledge knows, not where. The where is sarveṣu bhūteṣu (सर्वेषु भूतेषु), locative. nānā-bhāvān (नाना-भावान्) is accusative plural, the object of vetti (वेत्ति). The suffix --tva (त्व) on pṛthak (पृथक्) makes the noun "separateness," and --ena (एन) makes the instrumental. In 18.20 the means was yena (येन), "by which," pointing at the knowledge. Here the means is named outright.

Say it back

Cover the English. Say what this knowledge sees, and that it sees them as separate. If it sees one avyayam (अव्ययम्), you are still in 18.20.