महाभारतः mahābhārataḥ - book-12, chapter-234, verse-6

ब्रह्मचर्येण वै लोकाञ्जयन्ति परमर्षयः ।
आत्मनश्च हृदि श्रेयस्त्वन्विच्छ मनसात्मनि ॥६॥

6. brahmacaryeṇa vai lokāñjayanti paramarṣayaḥ ,
ātmanaśca hṛdi śreyastvanviccha manasātmani.

6. brahmacaryeṇa vai lokān jayanti paramarṣayaḥ
ātmanaḥ ca hṛdi śreyaḥ tu anviccha manasā ātmani

6. paramarṣayaḥ vai brahmacaryeṇa lokān jayanti ca
[tvam] manasā ātmanaḥ śreyaḥ hṛdi ātmani tu anviccha

6. Truly, great sages conquer worlds through spiritual discipline (brahmacarya). And you, by your mind, should seek the ultimate good (śreyas) for the self (ātman) within your own heart, in your self (ātman).

Words meanings summery:

• ब्रह्मचर्येण (brahmacaryeṇa) - by spiritual discipline, by celibacy, by a student's life of religious study

• वै (vai) - indeed, surely, verily

• लोकान् (lokān) - worlds, realms, planes of existence

• जयन्ति (jayanti) - they conquer, they overcome, they win

• परमर्षयः (paramarṣayaḥ) - great sages, supreme seers

• आत्मनः (ātmanaḥ) - of the self, of the soul

• च (ca) - and, also

• हृदि (hṛdi) - in the heart, in the mind

• श्रेयः (śreyaḥ) - the ultimate good, welfare, benefit, prosperity

• तु (tu) - but, and, on the other hand

• अन्विच्छ (anviccha) - seek, search for, desire

• मनसा (manasā) - by the mind, with the mind, mentally

• आत्मनि (ātmani) - in the self, within oneself, in the soul

Words meanings and morphology

ब्रह्मचर्येण (brahmacaryeṇa) - by spiritual discipline, by celibacy, by a student's life of religious study

(noun)

Instrumental, neuter, singular of brahmacarya

brahmacarya - spiritual discipline, religious studentship, celibacy, chaste conduct

Compound type : tatpuruṣa (brahman+carya)

• brahman – Ultimate Reality, sacred word, Vedic knowledge
  noun (neuter)
• carya – conduct, practice, course of action
  noun (neuter)
  Gerundive
  Derived from √car (to move, to practice) with suffix -ya
  Root: √car (class 1)

वै (vai) - indeed, surely, verily

(indeclinable)

लोकान् (lokān) - worlds, realms, planes of existence

(noun)

Accusative, masculine, plural of loka

loka - world, realm, people, space

जयन्ति (jayanti) - they conquer, they overcome, they win

(verb)

3rd person , plural, active, present (laṭ) of √ji

Root: √ji (class 1)

परमर्षयः (paramarṣayaḥ) - great sages, supreme seers

(noun)

Nominative, masculine, plural of paramarṣi

paramarṣi - great sage, supreme seer

Compound type : karmadhāraya (parama+ṛṣi)

• parama – supreme, highest, ultimate
  adjective (masculine)
• ṛṣi – sage, seer, inspired poet
  noun (masculine)

आत्मनः (ātmanaḥ) - of the self, of the soul

(noun)

Genitive, masculine, singular of ātman

ātman - self, soul, spirit, essence, breath

च (ca) - and, also

(indeclinable)

हृदि (hṛdi) - in the heart, in the mind

(noun)

Locative, neuter, singular of hṛd

hṛd - heart, mind, core, essence

श्रेयः (śreyaḥ) - the ultimate good, welfare, benefit, prosperity

(noun)

Nominative, neuter, singular of śreyas

śreyas - good, excellence, welfare, ultimate good, salvation

तु (tu) - but, and, on the other hand

(indeclinable)

अन्विच्छ (anviccha) - seek, search for, desire

(verb)

2nd person , singular, active, imperative (loṭ) of √iṣ

Prefix: anu

Root: √iṣ (class 4)

मनसा (manasā) - by the mind, with the mind, mentally

(noun)

Instrumental, neuter, singular of manas

manas - mind, intellect, thought, intention

आत्मनि (ātmani) - in the self, within oneself, in the soul

(noun)

Locative, masculine, singular of ātman

ātman - self, soul, spirit, essence, breath