3.24

उत्सीदेयुरिमे लोका न कुर्यां कर्म चेदहम् ।
सङ्करस्य च कर्ता स्यामुपहन्यामिमाः प्रजाः ॥

utsīdeyur ime lokā na kuryāṃ karma ced aham
saṅkarasya ca kartā syām upahanyām imāḥ prajāḥ

śrībhagavān (श्रीभगवान्) is speaking, the yadi (यदि) of 3.23 now appearing as cet (चेत्).

The verse

These worlds would sink if I did not do action; I would be the maker of mixture, and I would destroy these creatures.

नेपालीमा

यदि म कर्म नगरेँ भने यी लोकहरू डुब्थे। म मिश्रण उत्पन्न गर्ने हुन्थेँ र यी प्राणीहरूलाई नाश गर्थेँ।

Where it sits

The personal claim of 3.22 is now a reason about the world: he acts so the worlds do not take his idleness as the standard. 3.25 hands that same standard to the wise man.

Split: उत्सीदेयुः + इमे + लोकाः + न + कुर्याम् + कर्म + चेत् + अहम् + सङ्करस्य + च + कर्ता + स्याम् + उपहन्याम् + इमाः + प्रजाः

utsīdeyuḥ + ime + lokāḥ + na + kuryām + karma + cet + aham + saṅkarasya + ca + kartā + syām + upahanyām + imāḥ + prajāḥ

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
उत्सीदेयुःutsīdeyuḥoptative, 3rd plural of ut-sad (उत्-सद्)they would sink, they would go to ruin.
इमेimenominative pluralthese.
लोकाःlokāḥnominative pluralworlds.
नnaindeclinablenot.
कुर्याम्kuryāmoptative, 1st singular of kṛ (कृ)I would do.
कर्मkarmaaccusativeaction.
चेत्cetindeclinableif.
अहम्ahamnominativeI.
सङ्करस्यsaṅkarasyagenitiveof mixture, of the confounding of orders.
चcaindeclinableand.
कर्ताkartānominative of kartṛ (कर्तृ)the maker, the author.
स्याम्syāmoptative, 1st singular of as (अस्)I would be.
उपहन्याम्upahanyāmoptative, 1st singular of upa-han (उप-हन्)I would strike down, I would destroy.
इमाःimāḥaccusative pluralthese.
प्रजाःprajāḥaccusative pluralcreatures.

The phrases

उत्सीदेयुः इमे लोकाः utsīdeyur ime lokāḥ is the result, stated before the if. These worlds would sink. उः + इ uḥ + i is ur (उर्): utsīdeyur ime (उत्सीदेयुरिमे). lokāḥ (लोकाः) before na (न) loses its visarga: lokā na (लोका न).

न कुर्याम् कर्म चेत् अहम् na kuryāṃ karma ced aham is the if, late in the line. If I did not do action. चेत् + अहम् cet + aham voices the t (त्): ced aham (चेदहम्).

सङ्करस्य च कर्ता स्याम् उपहन्याम् इमाः प्रजाः saṅkarasya ca kartā syām upahanyām imāḥ prajāḥ is what he would become. I would be the maker of mixture, and I would destroy these creatures. स्याम् + उपहन्याम् + इमाः syām + upahanyām + imāḥ is one cluster: syām upahanyām imāḥ (स्यामुपहन्यामिमाः).

Sanskrit in this line

utsīdeyuḥ (उत्सीदेयुः) is optative, third person plural, "they would sink." The ending --yuḥ (युः) is the plural of that mood. It is not a past tense. The worlds have not sunk. The cet (चेत्) keeps the ruin on the far side of an if.

Say it back

What would sink, and what he would be the author of. If saṅkara (सङ्कर) becomes "a war," stay here. It is the mixing that follows when the standard collapses.