योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-43, verse-31

तत्पूजनेन कष्टेन तपसा तस्य राघव ।
काले निर्मलतामेति चित्तं वैराग्यकारिणा ॥ ३१ ॥

tatpūjanena kaṣṭena tapasā tasya rāghava ,
kāle nirmalatāmeti cittaṃ vairāgyakāriṇā 31

31. tatpūjanena kaṣṭena tapasā tasya rāghava
kāle nirmalatām eti cittam vairāgyakāriṇā

31. rāghava tasya tatpūjanena kaṣṭena vairāgyakāriṇā
tapasā kāle cittam nirmalatām eti

31. O descendant of Raghu (Rāghava), through worship of him and through the arduous spiritual discipline (tapas) that generates dispassion (vairāgya), one's mind (citta) eventually attains purity.

Words meanings summery:

• तत्पूजनेन (tatpūjanena) - by his worship, by that worship

• कष्टेन (kaṣṭena) - by hardship, by difficulty, by suffering

• तपसा (tapasā) - by asceticism, by spiritual discipline (tapas)

• तस्य (tasya) - his, of him, of that

• राघव (rāghava) - O descendant of Raghu (Rāma)

• काले (kāle) - in time, in due course

• निर्मलताम् (nirmalatām) - purity, stainlessness

• एति (eti) - attains, goes, reaches

• चित्तम् (cittam) - mind, consciousness

• वैराग्यकारिणा (vairāgyakāriṇā) - by that which produces dispassion (vairāgya)

Words meanings and morphology

तत्पूजनेन (tatpūjanena) - by his worship, by that worship

(noun)

Instrumental, neuter, singular of tatpūjana

tatpūjana - worship of him/that

Compound type : tatpuruṣa (tad+pūjana)

• tad – that, his
  pronoun (neuter)
• pūjana – worship, adoration, honoring
  noun (neuter)
  action noun
  from root pūj (to worship)
  Root: pūj (class 10)

कष्टेन (kaṣṭena) - by hardship, by difficulty, by suffering

(noun)

Instrumental, neuter, singular of kaṣṭa

kaṣṭa - hardship, difficulty, pain, suffering

तपसा (tapasā) - by asceticism, by spiritual discipline (tapas)

(noun)

Instrumental, neuter, singular of tapas

tapas - asceticism, spiritual discipline, penance, heat

तस्य (tasya) - his, of him, of that

(pronoun)

Genitive, masculine, singular of tad

tad - that, he, she, it

राघव (rāghava) - O descendant of Raghu (Rāma)

(proper noun)

Vocative, masculine, singular of rāghava

rāghava - descendant of Raghu, Rāma

patronymic from Raghu

काले (kāle) - in time, in due course

(noun)

Locative, masculine, singular of kāla

kāla - time, period, season

निर्मलताम् (nirmalatām) - purity, stainlessness

(noun)

Accusative, feminine, singular of nirmalatā

nirmalatā - purity, cleanness, stainlessness

derived from nirmala (pure) + tā (suffix for abstract noun)

एति (eti) - attains, goes, reaches

(verb)

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

Root: i (class 2)

चित्तम् (cittam) - mind, consciousness

(noun)

Nominative, neuter, singular of citta

citta - mind, consciousness, thought

Past Passive Participle of cit (to perceive, understand), used as a noun

Root: cit (class 1)

वैराग्यकारिणा (vairāgyakāriṇā) - by that which produces dispassion (vairāgya)

(adjective)

Instrumental, neuter, singular of vairāgyakārin

vairāgyakārin - causing/producing dispassion

Compound type : tatpuruṣa (vairāgya+kārin)

• vairāgya – dispassion, detachment, indifference, freedom from worldly desires
  noun (neuter)
  from virāga (absence of passion)
• kārin – causing, producing, doing
  adjective (masculine/neuter/feminine)
  agent noun
  from root kṛ (to do, make)
  Root: kṛ (class 8)

Note: Agrees with 'tapasā' (neuter, instrumental).