4.13

चातुर्वर्ण्यं मया सृष्टं गुणकर्मविभागशः ।
तस्य कर्तारमपि मां विद्ध्यकर्तारमव्ययम् ॥

cāturvarṇyaṃ mayā sṛṣṭaṃ guṇakarmavibhāgaśaḥ
tasya kartāram api māṃ viddhy akartāram avyayam

Kṛṣṇa (कृष्ण) is still speaking, to Arjuna.

The verse

The fourfold order was sent forth by me, according to the division of qualities and actions; know me as its maker and also as no maker, imperishable.

नेपालीमा

चार भागको वर्ण मैले गुण र कर्मको छुट्याइअनुसार रचेँ। मलाई त्यसको रचनाकार पनि, अकर्ता पनि, अविनाशी पनि बुझ।

Where it sits

The sacrifices of 4.12 sit inside a human order, and this verse says he sent that order forth while refusing the conclusion that he is bound as its doer. 4.14 will say the same thing as a rule about action and fruit.

Split: चातुर्वर्ण्यम् + मया + सृष्टम् + गुण-कर्म-विभागशः + तस्य + कर्तारम् + अपि + माम् + विद्धि + अकर्तारम् + अव्ययम्

cāturvarṇyam + mayā + sṛṣṭam + guṇa-karma-vibhāgaśaḥ + tasya + kartāram + api + mām + viddhi + akartāram + avyayam

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
चातुर्वर्ण्यम्cāturvarṇyamnominative neuterthe fourfold order. From catur (चतुर्) "four" and varṇa (वर्ण), with an abstract suffix.
मयाmayāinstrumentalby me.
सृष्टम्sṛṣṭamnominative neutersent forth, made. Agrees with cāturvarṇyam (चातुर्वर्ण्यम्).
गुण-कर्म-विभागशःguṇa-karma-vibhāgaśaḥindeclinableaccording to the division of qualities and actions. --śas (शस्), as in sarvaśaḥ (सर्वशः) in 4.11.
तस्यtasyagenitiveof that. Of the fourfold order.
कर्तारम्kartāramaccusativethe maker, the doer.
अपिapiindeclinableeven, also.
माम्māmaccusativeme.
विद्धिviddhiimperative, 2nd singularknow. From vid (विद्).
अकर्तारम्akartāramaccusativethe non-maker. The same noun with a- (अ-).
अव्ययम्avyayamaccusativeimperishable. Agrees with the "me" he is told to know.

The phrases

cāturvarṇyaṃ mayā sṛṣṭaṃ guṇakarmavibhāgaśaḥ (चातुर्वर्ण्यं मया सृष्टं गुणकर्मविभागशः) is the making. The fourfold order was sent forth by me, according to the division of qualities and of actions. mayā (मया) is the maker in the instrumental, with a passive participle. There is no "I made" verb.

तस्य कर्तारम् अपि मां विद्धि अकर्तारम् अव्ययम् tasya kartāram api māṃ viddhi akartāram avyayam is the command that keeps the making from sticking. Know me as the maker of that, and also as no maker, imperishable. viddhi akartāram (विद्धि अकर्तारम्) is viddhy akartāram (विद्ध्यकर्तारम्). kartāram (कर्तारम्) and akartāram (अकर्तारम्) are both accusative, both him.

Sanskrit in this line

viddhi (विद्धि) is the imperative, "know." It takes mām (माम्) as the object, and then two further accusatives that say what to know him as: kartāram (कर्तारम्) and akartāram (अकर्तारम्). इ + अ i + a joins the imperative to the second of those: viddhi akartāram (विद्धि अकर्तारम्) is viddhy akartāram (विद्ध्यकर्तारम्). The a- (अ-) on akartāram (अकर्तारम्) is the negative prefix, the one from 1.10, not a past tense.

Say it back

What he sent forth, and the two ways he is to be known. If akartāram (अकर्तारम्) is smoothed into the same word as kartāram (कर्तारम्), stay here.