महाभारतः mahābhārataḥ - book-6, chapter-54, verse-23

शुशुभाते तदा तौ तु शैनेयकुरुपुंगवौ ।
अमावास्यां गतौ यद्वत्सोमसूर्यौ नभस्तले ॥२३॥

23. śuśubhāte tadā tau tu śaineyakurupuṁgavau ,
amāvāsyāṁ gatau yadvatsomasūryau nabhastale.

23. śuśubhāte tadā tau tu śaineyakurupuṅgavau
amāvāsyām gatau yadvat somasūryau nabhastale

23. tadā tau tu śaineyakurupuṅgavau nabhastale
amāvāsyām gatau somasūryau yadvat śuśubhāte

23. Then, those two, Satyaki (the descendant of Shini) and Abhimanyu (the foremost of the Kurus), shone brightly, just as the Moon and the Sun appear together in the sky on a new moon day.

Words meanings summery:

• शुशुभाते (śuśubhāte) - they shone, they appeared beautiful

• तदा (tadā) - then, at that time

• तौ (tau) - those two

• तु (tu) - but, indeed, however

• शैनेयकुरुपुङ्गवौ (śaineyakurupuṅgavau) - Satyaki (descendant of Shini) and Abhimanyu (foremost of the Kurus)

• अमावास्याम् (amāvāsyām) - on the new moon day

• गतौ (gatau) - appearing (having gone, being (in a state of))

• यद्वत् (yadvat) - just as, like

• सोमसूर्यौ (somasūryau) - the Moon and the Sun

• नभस्तले (nabhastale) - in the sky

Words meanings and morphology

शुशुभाते (śuśubhāte) - they shone, they appeared beautiful

(verb)

3rd person , dual, middle, perfect (lit) of śubh

Root: śubh (class 1)

तदा (tadā) - then, at that time

(indeclinable)

तौ (tau) - those two

(pronoun)

Nominative, masculine, dual of tad

tad - that, he, she, it

तु (tu) - but, indeed, however

(indeclinable)

शैनेयकुरुपुङ्गवौ (śaineyakurupuṅgavau) - Satyaki (descendant of Shini) and Abhimanyu (foremost of the Kurus)

(proper noun)

Nominative, masculine, dual of śaineyakurupuṅgava

śaineyakurupuṅgava - Satyaki (a descendant of Shini) and the best of the Kurus (Abhimanyu)

Compound type : dvandva (śaineya+kurupuṅgava)

• śaineya – descendant of Shini (Satyaki)
  proper noun (masculine)
  Patronymic from Shini.
• kurupuṅgava – foremost of the Kurus
  compound (masculine)

अमावास्याम् (amāvāsyām) - on the new moon day

(noun)

Locative, feminine, singular of amāvāsyā

amāvāsyā - new moon day

गतौ (gatau) - appearing (having gone, being (in a state of))

(adjective)

Nominative, masculine, dual of gata

gata - gone, arrived, being in, obtained

Past Passive Participle

Derived from the root √gam (to go).

Root: gam (class 1)

यद्वत् (yadvat) - just as, like

(indeclinable)

सोमसूर्यौ (somasūryau) - the Moon and the Sun

(noun)

Nominative, masculine, dual of somasūrya

somasūrya - the Moon and the Sun

Compound type : dvandva (soma+sūrya)

• soma – Moon
  noun (masculine)
• sūrya – Sun
  noun (masculine)

नभस्तले (nabhastale) - in the sky

(noun)

Locative, neuter, singular of nabhastala

nabhastala - surface of the sky, firmament

Compound type : ṣaṣṭhī tatpuruṣa (nabhas+tala)

• nabhas – sky, atmosphere, heaven
  noun (neuter)
• tala – surface, plain, level
  noun (masculine)