महाभारतः mahābhārataḥ - book-3, chapter-83, verse-4

गङ्गायास्त्वथ राजेन्द्र सागरस्य च संगमे ।
अश्वमेधं दशगुणं प्रवदन्ति मनीषिणः ॥४॥

4. gaṅgāyāstvatha rājendra sāgarasya ca saṁgame ,
aśvamedhaṁ daśaguṇaṁ pravadanti manīṣiṇaḥ.

4. gaṅgāyāḥ tu atha rājendra sāgarasya ca saṅgame
aśvamedham daśaguṇam pravadanti manīṣiṇaḥ

4. O king of kings (rājendra), the wise (manīṣin) declare that a horse sacrifice (aśvamedha) performed at the confluence of the Gaṅgā and the ocean yields a ten-fold benefit.

Words meanings summery:

• गङ्गायाः (gaṅgāyāḥ) - of the Gaṅgā

• तु (tu) - but, indeed, and, moreover

• अथ (atha) - then, thereafter, and

• राजेन्द्र (rājendra) - O king of kings, O mighty king

• सागरस्य (sāgarasya) - of the ocean

• च (ca) - and

• सङ्गमे (saṅgame) - at the confluence, at the meeting point

• अश्वमेधम् (aśvamedham) - horse sacrifice (aśvamedha)

• दशगुणम् (daśaguṇam) - ten-fold, ten times, having ten qualities

• प्रवदन्ति (pravadanti) - they declare, they proclaim, they say

• मनीषिणः (manīṣiṇaḥ) - the wise ones, the discerning ones, the learned

Words meanings and morphology

गङ्गायाः (gaṅgāyāḥ) - of the Gaṅgā

(proper noun)

Genitive, feminine, singular of gaṅgā

gaṅgā - the river Ganges, Gaṅgā

तु (tu) - but, indeed, and, moreover

(indeclinable)

अथ (atha) - then, thereafter, and

(indeclinable)

राजेन्द्र (rājendra) - O king of kings, O mighty king

(noun)

Vocative, masculine, singular of rājendra

rājendra - king of kings, an emperor, a mighty king

Compound type : tatpurusha (rājan+indra)

• rājan – king
  noun (masculine)
• indra – Indra, chief, best
  noun (masculine)

सागरस्य (sāgarasya) - of the ocean

(noun)

Genitive, masculine, singular of sāgara

sāgara - ocean, sea

च (ca) - and

(indeclinable)

सङ्गमे (saṅgame) - at the confluence, at the meeting point

(noun)

Locative, masculine, singular of saṅgama

saṅgama - confluence, meeting, junction

अश्वमेधम् (aśvamedham) - horse sacrifice (aśvamedha)

(noun)

Accusative, masculine, singular of aśvamedha

aśvamedha - horse sacrifice, a type of Vedic ritual

दशगुणम् (daśaguṇam) - ten-fold, ten times, having ten qualities

(adjective)

Accusative, masculine, singular of daśaguṇa

daśaguṇa - ten-fold, ten times, having ten qualities

Compound type : bahuvrihi (daśa+guṇa)

• daśa – ten
  numeral
• guṇa – quality, attribute, virtue, fold, times (as in 'ten-fold')
  noun (masculine)

प्रवदन्ति (pravadanti) - they declare, they proclaim, they say

(verb)

3rd person , plural, active, present indicative (laṭ) of pravad

Prefix: pra

Root: vad (class 1)

मनीषिणः (manīṣiṇaḥ) - the wise ones, the discerning ones, the learned

(noun)

Nominative, masculine, plural of manīṣin

manīṣin - wise, intelligent, discerning, a learned person