योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-41, verse-8

यथाकथंचिदङ्गारे निघृष्य क्षालयञ्छिशुः ।
करनैर्मल्यमाप्नोति कार्ष्ण्याङ्गारक्षये यथा ॥ ८ ॥

yathākathaṃcidaṅgāre nighṛṣya kṣālayañchiśuḥ ,
karanairmalyamāpnoti kārṣṇyāṅgārakṣaye yathā 8

8. yathākathaṃcit aṅgāre nighṛṣya kṣālayat śiśuḥ
karanairmalyam āpnoti kārṣṇyāṅgārakṣaye yathā

8. yathākathaṃcit aṅgāre nighṛṣya kṣālayat śiśuḥ
kārṣṇyāṅgārakṣaye karanairmalyam āpnoti yathā

8. Just as a child, by somehow or other rubbing and washing (his hands) on charcoal, attains cleanliness of hands when both the blackness and the charcoal itself are destroyed.

Words meanings summery:

• यथाकथंचित् (yathākathaṁcit) - somehow or other, in any way, with difficulty

• अङ्गारे (aṅgāre) - on charcoal, on live coal

• निघृष्य (nighṛṣya) - having rubbed, by rubbing

• क्षालयत् (kṣālayat) - washing, cleansing

• शिशुः (śiśuḥ) - child, infant

• करनैर्मल्यम् (karanairmalyam) - cleanliness of hands

• आप्नोति (āpnoti) - obtains, attains, reaches

• कार्ष्ण्याङ्गारक्षये (kārṣṇyāṅgārakṣaye) - when the blackness (from charcoal) and the charcoal itself are destroyed/removed (in the destruction of blackness and charcoal)

• यथा (yathā) - just as, as

Words meanings and morphology

यथाकथंचित् (yathākathaṁcit) - somehow or other, in any way, with difficulty

(indeclinable)

compound of yathā, kathaṃ, and cit

Compound type : avyayībhāva (yathā+katham+cit)

• yathā – as, in which way
  indeclinable
• katham – how, in what manner
  indeclinable
• cit – even, indeed (emphatic particle)
  indeclinable

अङ्गारे (aṅgāre) - on charcoal, on live coal

(noun)

Locative, masculine, singular of aṅgāra

aṅgāra - charcoal, live coal, cinder

निघृष्य (nighṛṣya) - having rubbed, by rubbing

(indeclinable)

absolutive

ni + ghṛṣ + lyap suffix

Prefix: ni

Root: ghṛṣ (class 1)

क्षालयत् (kṣālayat) - washing, cleansing

(adjective)

Nominative, masculine, singular of kṣālayant

kṣālayant - washing, cleansing

present active participle

causative stem of kṣal + śatṛ suffix

Root: kṣal (class 1)

शिशुः (śiśuḥ) - child, infant

(noun)

Nominative, masculine, singular of śiśu

śiśu - child, infant, young animal

करनैर्मल्यम् (karanairmalyam) - cleanliness of hands

(noun)

Accusative, neuter, singular of karanairmalya

karanairmalya - cleanliness of hands, purity of hands

Compound type : ṣaṣṭhī-tatpuruṣa (kara+nairmalya)

• kara – hand, ray, tax
  noun (masculine)
• nairmalya – cleanliness, purity, spotlessness
  noun (neuter)

आप्नोति (āpnoti) - obtains, attains, reaches

(verb)

3rd person , singular, active, present (lat) of āp

Prefix: ā

Root: āp (class 5)

कार्ष्ण्याङ्गारक्षये (kārṣṇyāṅgārakṣaye) - when the blackness (from charcoal) and the charcoal itself are destroyed/removed (in the destruction of blackness and charcoal)

(noun)

Locative, masculine, singular of kārṣṇyāṅgārakṣaya

kārṣṇyāṅgārakṣaya - destruction of blackness and charcoal

Compound type : dvandva-tatpuruṣa (kārṣṇya+aṅgāra+kṣaya)

• kārṣṇya – blackness, dark color
  noun (neuter)
  derived from kṛṣṇa (black)
• aṅgāra – charcoal, live coal
  noun (masculine)
• kṣaya – destruction, decay, end, disappearance
  noun (masculine)

Note: locative absolute construction

यथा (yathā) - just as, as

(indeclinable)