महाभारतः mahābhārataḥ - book-1, chapter-58, verse-51

तं भुवः शोधनायेन्द्र उवाच पुरुषोत्तमम् ।
अंशेनावतरस्वेति तथेत्याह च तं हरिः ॥५१॥

51. taṁ bhuvaḥ śodhanāyendra uvāca puruṣottamam ,
aṁśenāvatarasveti tathetyāha ca taṁ hariḥ.

51. tam bhuvaḥ śodhanāya indraḥ uvāca puruṣottamam
aṃśena avatarasva iti tathā iti āha ca tam hariḥ

51. Indra said to the Supreme Person (Narayana), for the purification of the earth, "Descend with a portion of yourself." Hari (Vishnu) then said to him, "So be it."

Words meanings summery:

• तम् (tam) - to him (referring to Purushottama/Narayana) (him, that (one))

• भुवः (bhuvaḥ) - of the earth (of the earth, of the world)

• शोधनाय (śodhanāya) - for the purification (for purification, for cleansing, for removal)

• इन्द्रः (indraḥ) - Indra (Indra (king of the gods))

• उवाच (uvāca) - said (he said, he spoke)

• पुरुषोत्तमम् (puruṣottamam) - to the Supreme Person (epithet of Vishnu/Narayana) (best among men, supreme person)

• अंशेन (aṁśena) - with a portion (of yourself) (by a part, with a portion)

• अवतरस्व (avatarasva) - descend (descend (you)!)

• इति (iti) - thus (concluding the quote) (thus, so, indicating quoted speech)

• तथा (tathā) - so be it (so, thus, in that manner)

• इति (iti) - thus (indicating agreement) (thus, so, indicating quoted speech)

• आह (āha) - said (he said, he spoke)

• च (ca) - then, also (and, also, moreover)

• तम् (tam) - to him (referring to Indra) (him, that (one))

• हरिः (hariḥ) - Hari (Hari (an epithet of Vishnu))

Words meanings and morphology

तम् (tam) - to him (referring to Purushottama/Narayana) (him, that (one))

(pronoun)

Accusative, masculine, singular of tad

tad - that, he, she, it

भुवः (bhuvaḥ) - of the earth (of the earth, of the world)

(noun)

Genitive, feminine, singular of bhū

bhū - earth, ground, world

शोधनाय (śodhanāya) - for the purification (for purification, for cleansing, for removal)

(noun)

Dative, neuter, singular of śodhana

śodhana - purification, cleansing, removal

action noun

from root śudh with suffix -ana

Root: śudh (class 4)

Note: Can be masculine or neuter; dative case indicates purpose.

इन्द्रः (indraḥ) - Indra (Indra (king of the gods))

(noun)

Nominative, masculine, singular of indra

indra - Indra (king of the gods)

उवाच (uvāca) - said (he said, he spoke)

(verb)

3rd person , singular, active, perfect (lit) of vac

Root: vac (class 2)

पुरुषोत्तमम् (puruṣottamam) - to the Supreme Person (epithet of Vishnu/Narayana) (best among men, supreme person)

(noun)

Accusative, masculine, singular of puruṣottama

puruṣottama - best among men, Supreme Person (epithet of Vishnu)

Compound type : tatpurusha (puruṣa+uttama)

• puruṣa – man, person, being
  noun (masculine)
• uttama – highest, best, supreme
  adjective (masculine)

अंशेन (aṁśena) - with a portion (of yourself) (by a part, with a portion)

(noun)

Instrumental, masculine, singular of aṃśa

aṁśa - part, portion, share

अवतरस्व (avatarasva) - descend (descend (you)!)

(verb)

2nd person , singular, active, imperative (lot) of avatṛ

Prefix: ava

Root: tṛ (class 1)

इति (iti) - thus (concluding the quote) (thus, so, indicating quoted speech)

(indeclinable)

तथा (tathā) - so be it (so, thus, in that manner)

(indeclinable)

इति (iti) - thus (indicating agreement) (thus, so, indicating quoted speech)

(indeclinable)

आह (āha) - said (he said, he spoke)

(verb)

3rd person , singular, active, perfect (lit) of ah

Root: ah (class 2)

च (ca) - then, also (and, also, moreover)

(indeclinable)

तम् (tam) - to him (referring to Indra) (him, that (one))

(pronoun)

Accusative, masculine, singular of tad

tad - that, he, she, it

हरिः (hariḥ) - Hari (Hari (an epithet of Vishnu))

(noun)

Nominative, masculine, singular of hari

hari - Hari (epithet of Vishnu/Krishna), tawny, yellowish, lion