8.26

शुक्लकृष्णे गती ह्येते जगतः शाश्वते मते ।
एकया यात्यनावृत्तिमन्ययावर्तते पुनः ॥

śuklakṛṣṇe gatī hy ete jagataḥ śāśvate mate
ekayā yāty anāvṛttim anyayāvartate punaḥ

Kṛṣṇa (कृष्ण) continues. The two lists become two paths.

The verse

These two, the bright and the dark, are held to be the eternal paths of the world. By one he goes to non-return. By the other he returns again.

नेपालीमा

यी दुई, उज्यालो र अँध्यारो, संसारका नित्य मार्ग मानिन्छन्। एउटाले ऊ नफर्कनेतिर जान्छ, अर्कोले फेरि फर्किन्छ।

Where it sits

The lists are gathered. Two paths, both old, both of this world. One does not return. One does. 8.27 will say that a yogin who knows the two is not confused, and will give the order again: at all times be yoked.

Split: शुक्ल-कृष्णे + गती + हि + एते + जगतः + शाश्वते + मते + एकया + याति + अनावृत्तिम् + अन्यया + आवर्तते + पुनः

śukla-kṛṣṇe + gatī + hi + ete + jagataḥ + śāśvate + mate + ekayā + yāti + anāvṛttim + anyayā + āvartate + punaḥ

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
शुक्ल-कृष्णेśukla-kṛṣṇenominative dual femininethe bright and the dark. Dual, agreeing with gatī (गती).
गतीgatīnominative dual of gati (गति)the two paths, the two goings.
हिhiindeclinableindeed.
एतेetenominative dualthese two.
जगतःjagataḥgenitive of jagat (जगत्)of the world.
शाश्वतेśāśvatenominative dual femininethe two eternal ones. Agrees with gatī (गती).
मतेmatenominative dual feminine, past participle of man (मन्)regarded, held to be.
एकयाekayāinstrumental feminineby the one.
यातिyātipresent, 3rd singularhe goes.
अनावृत्तिम्anāvṛttimaccusativeto non-return.
अन्ययाanyayāinstrumental feminineby the other.
आवर्ततेāvartatepresent, 3rd singular, middlehe returns.
पुनःpunaḥindeclinableagain.

The phrases

śuklakṛṣṇe gatī hi ete (शुक्लकृष्णे गती हि एते) names them as a pair. These two paths, the bright and the dark. Dual, not plural. 8.24 was the bright. 8.25 was the dark. jagataḥ śāśvate mate (जगतः शाश्वते मते) says the world holds them to be the two eternal paths. śāśvate (शाश्वते) and mate (मते) are dual with gatī (गती).

ekayā yāti anāvṛttim (एकया याति अनावृत्तिम्) is the bright path's result, from 8.24. By the one, he goes to non-return. anyayā āvartate punaḥ (अन्यया आवर्तते पुनः) is the dark path's result, from 8.25. By the other, he returns again. ekayā (एकया) and anyayā (अन्यया) are instrumental feminine, "by means of" each path. gati (गति) is feminine, so "one" and "other" are feminine.

Sanskrit in this line

gati (गति) in the dual nominative is gatī (गती), with a long ī (ई). That long vowel is the dual, not a feminine singular. śuklakṛṣṇe (शुक्लकृष्णे) is the dual of an a (अ)-stem, ending in e (ए). Same number, same gender, different stem, different ending. You do not "correct" gatī (गती) into gate (गते) to match śuklakṛṣṇe (शुक्लकृष्णे).

हि + एते hi + ete is hy ete (ह्येते). इ + ए i + e becomes ye (ये). अन्यया + आवर्तते anyayā + āvartate is anyayāvartate (अन्ययावर्तते). आ + आ ā + ā becomes ā (आ). The second path's verb is still āvartate (आवर्तते), "returns."

Say it back

Two paths, two results. If ekayā (एकया) and anyayā (अन्यया) are both made to return, or both made to stay, the dual has been wasted.