योगवासिष्ठः yogavāsiṣṭhaḥ - book-1, chapter-33, verse-37

कथंचित्क्वचिदेवैको दृश्यते विमलाशयः ।
पूर्वापरविचारार्हो यथायमरिमर्दनः ॥ ३७ ॥

kathaṃcitkvacidevaiko dṛśyate vimalāśayaḥ ,
pūrvāparavicārārho yathāyamarimardanaḥ 37

37. kathaṃcit kvacit eva ekaḥ dṛśyate vimala-āśayaḥ
pūrva-apara-vicāra-arhaḥ yathā ayam arimardanaḥ

37. kathaṃcit kvacit eva ekaḥ vimala-āśayaḥ dṛśyate
ayam arimardanaḥ yathā pūrva-apara-vicāra-arhaḥ

37. Rarely, here and there, a single individual with a pure mind is seen, one who is capable of considering past and future, just like you, O conqueror of foes (arimardana).

Words meanings summery:

• कथंचित् (kathaṁcit) - somehow; with difficulty; rarely

• क्वचित् (kvacit) - somewhere; sometimes; rarely

• एव (eva) - indeed; only; just; truly

• एकः (ekaḥ) - a single individual (one; a single one; alone)

• दृश्यते (dṛśyate) - is seen; appears

• विमल-आशयः (vimala-āśayaḥ) - one with a pure mind; clear-minded; pure-hearted

• पूर्व-अपर-विचार-अर्हः (pūrva-apara-vicāra-arhaḥ) - capable of reflecting upon what has happened and what will happen, i.e., consequences (worthy of considering past and future; capable of comprehensive reflection)

• यथा (yathā) - just as; as; for example

• अयम् (ayam) - this person, referring to the interlocutor (this (one))

• अरिमर्दनः (arimardanaḥ) - a heroic epithet for the person being addressed (conqueror of enemies; foe-crusher)

Words meanings and morphology

कथंचित् (kathaṁcit) - somehow; with difficulty; rarely

(indeclinable)

क्वचित् (kvacit) - somewhere; sometimes; rarely

(indeclinable)

एव (eva) - indeed; only; just; truly

(indeclinable)

एकः (ekaḥ) - a single individual (one; a single one; alone)

(pronoun)

Nominative, masculine, singular of eka

eka - one; a single; alone; unique; chief

Note: Used substantively.

दृश्यते (dṛśyate) - is seen; appears

(verb)

3rd person , singular, passive, present indicative (laṭ) of dṛś

Root: dṛś (class 1)

विमल-आशयः (vimala-āśayaḥ) - one with a pure mind; clear-minded; pure-hearted

(adjective)

Nominative, masculine, singular of vimala-āśaya

vimala-āśaya - having a pure mind or intention; clear-minded; pure-hearted

Compound type : bahuvrīhi (vimala+āśaya)

• vimala – spotless; pure; clean; free from blemish
  adjective
• āśaya – intention; mind; abode; receptacle; thought
  noun (masculine)

Note: Used substantively.

पूर्व-अपर-विचार-अर्हः (pūrva-apara-vicāra-arhaḥ) - capable of reflecting upon what has happened and what will happen, i.e., consequences (worthy of considering past and future; capable of comprehensive reflection)

(adjective)

Nominative, masculine, singular of pūrva-apara-vicāra-arha

pūrva-apara-vicāra-arha - deserving or capable of considering the former and the latter (i.e., past and future, or pros and cons)

Compound type : tatpuruṣa (pūrva+apara+vicāra+arha)

• pūrva – former; prior; eastern; what comes first
  adjective
• apara – later; subsequent; other; western
  adjective
• vicāra – consideration; reflection; investigation; deliberation
  noun (masculine)
• arha – worthy; deserving; suitable; capable
  adjective

यथा (yathā) - just as; as; for example

(indeclinable)

अयम् (ayam) - this person, referring to the interlocutor (this (one))

(pronoun)

Nominative, masculine, singular of idam

idam - this; this one

अरिमर्दनः (arimardanaḥ) - a heroic epithet for the person being addressed (conqueror of enemies; foe-crusher)

(noun)

Nominative, masculine, singular of arimardana

arimardana - destroyer of enemies; conqueror of foes

Compound type : upapada-tatpuruṣa (ari+mardana)

• ari – enemy; foe
  noun (masculine)
• mardana – crushing; destroying; conqueror
  noun (masculine)
  agent noun from root mṛd
  From root 'mṛd' (to crush, to rub) with '-ana' suffix
  Root: mṛd (class 9)