महाभारतः mahābhārataḥ - book-3, chapter-82, verse-50

अथ वेतसिकां गत्वा पितामहनिषेविताम् ।
अश्वमेधमवाप्नोति गच्छेच्चौशनसीं गतिम् ॥५०॥

50. atha vetasikāṁ gatvā pitāmahaniṣevitām ,
aśvamedhamavāpnoti gaccheccauśanasīṁ gatim.

50. atha vetasikām gatvā pitāmahanisevitām
aśvamedham avāpnoti gacchet ca auśanasīm gatim

50. Then, upon visiting Vetāśikā, a place frequented by the Grandfather (Brahmā), one obtains the benefit of an aśvamedha sacrifice and achieves the status of Uśanas.

Words meanings summery:

• अथ (atha) - then (then, now, moreover)

• वेतसिकाम् (vetasikām) - to the sacred place (tirtha) named Vetāśikā (to Vetāśikā (a sacred place))

• गत्वा (gatvā) - having gone

• पितामहनिसेविताम् (pitāmahanisevitām) - frequented by the Grandfather (Brahmā)

• अश्वमेधम् (aśvamedham) - the horse sacrifice (aśvamedha) (horse sacrifice)

• अवाप्नोति (avāpnoti) - obtains (attains, obtains)

• गच्छेत् (gacchet) - one attains (one should go, one should attain)

• च (ca) - and (and, also)

• औशनसीम् (auśanasīm) - pertaining to Uśanas (Śukra)

• गतिम् (gatim) - state, status (state, condition, destination, path)

Words meanings and morphology

अथ (atha) - then (then, now, moreover)

(indeclinable)

वेतसिकाम् (vetasikām) - to the sacred place (tirtha) named Vetāśikā (to Vetāśikā (a sacred place))

(proper noun)

Accusative, feminine, singular of vetasikā

vetasikā - name of a sacred place (tirtha)

गत्वा (gatvā) - having gone

(indeclinable)

absolutive (gerund)

formed from root gam + suffix -tvā

Root: gam (class 1)

पितामहनिसेविताम् (pitāmahanisevitām) - frequented by the Grandfather (Brahmā)

(adjective)

Accusative, feminine, singular of pitāmahanisevitā

pitāmahanisevitā - frequented by the grandfather

Compound type : tatpuruṣa (pitāmaha+niṣevitā)

• pitāmaha – grandfather; Brahmā
  noun (masculine)
• niṣevitā – frequented, attended, resorted to
  adjective (feminine)
  Past Passive Participle
  ni + sev + kta
  Prefix: ni
  Root: sev (class 1)

अश्वमेधम् (aśvamedham) - the horse sacrifice (aśvamedha) (horse sacrifice)

(noun)

Accusative, masculine, singular of aśvamedha

aśvamedha - horse sacrifice

अवाप्नोति (avāpnoti) - obtains (attains, obtains)

(verb)

3rd person , singular, active, present (laṭ) of avāp

present active

ava + āp, 3rd person singular, present tense

Prefix: ava

Root: āp (class 5)

गच्छेत् (gacchet) - one attains (one should go, one should attain)

(verb)

3rd person , singular, active, optative (liṅ) of gam

optative active

3rd person singular, optative mood

Root: gam (class 1)

Note: Used here to imply 'attains' a certain state or destination.

च (ca) - and (and, also)

(indeclinable)

औशनसीम् (auśanasīm) - pertaining to Uśanas (Śukra)

(adjective)

Accusative, feminine, singular of auśanasī

auśanasī - relating to Uśanas (Śukra), venusian

derived from Uśanas

गतिम् (gatim) - state, status (state, condition, destination, path)

(noun)

Accusative, feminine, singular of gati

gati - going, motion, course, way, state, condition, destination

from root gam

Root: gam (class 1)