योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-91, verse-10

सत्त्वात्मसु महासत्त्वं नित्यत्वं देवसद्मसु ।
जगज्जीर्णकुटीदीपः कूपोम्भस्तमसोर्महान् ॥ १० ॥

sattvātmasu mahāsattvaṃ nityatvaṃ devasadmasu ,
jagajjīrṇakuṭīdīpaḥ kūpombhastamasormahān 10

10. sattvātmāsu mahāsattvam nityatvam devasadmasu
jagat jīrṇakuṭīdīpaḥ kūpombhastamasoḥ mahān

10. sattvātmāsu devasadmasu mahāsattvam nityatvam
jagat jīrṇakuṭīdīpaḥ kūpombhastamasoḥ mahān

10. Great purity and eternal presence exist among those whose intrinsic nature (ātman) is goodness (sattva) and in divine abodes. The world is but a lamp in a dilapidated hut. And a great entity (mahān) is found in well-water and in darkness.

Words meanings summery:

• सत्त्वात्मासु (sattvātmāsu) - in noble souls (in those whose nature (ātman) is goodness (sattva))

• महासत्त्वम् (mahāsattvam) - great purity (great goodness, great essence, great being)

• नित्यत्वम् (nityatvam) - eternal presence (eternity, permanence, constancy)

• देवसद्मसु (devasadmasu) - in divine abodes, in temples

• जगत् (jagat) - the world (world, universe, moving)

• जीर्णकुटीदीपः (jīrṇakuṭīdīpaḥ) - lamp of a dilapidated hut

• कूपोम्भस्तमसोः (kūpombhastamasoḥ) - in well-water and in darkness (of well-water and darkness; in well-water and darkness)

• महान् (mahān) - a great entity (referring to a divine being or principle) (great, mighty, large)

Words meanings and morphology

सत्त्वात्मासु (sattvātmāsu) - in noble souls (in those whose nature (ātman) is goodness (sattva))

(noun)

Locative, masculine, plural of sattvātmā

sattvātmā - one whose intrinsic nature (ātman) is goodness (sattva)

Compound sattva + ātman. sattva here is the guṇa of purity/goodness.

Compound type : bahuvrīhi (sattva+ātman)

• sattva – essence, existence, reality, goodness, purity, strength; a living being
  noun (neuter)
  From root as (to be) or sat (being)
  Root: as (class 2)
• ātman – self, soul, spirit, individual essence, vital breath, intrinsic nature
  noun (masculine)
  From root an (to breathe)
  Root: an (class 2)

महासत्त्वम् (mahāsattvam) - great purity (great goodness, great essence, great being)

(noun)

Nominative, neuter, singular of mahāsattva

mahāsattva - great essence, great being, great goodness, great strength

Compound mahā (great) + sattva (essence/goodness).

Compound type : karmadhāraya (mahā+sattva)

• mahā – great, large, mighty
  adjective
  Stem of mahat.
• sattva – essence, existence, reality, goodness, purity, strength; a living being
  noun (neuter)
  From root as (to be) or sat (being)
  Root: as (class 2)

Note: Predicate nominative.

नित्यत्वम् (nityatvam) - eternal presence (eternity, permanence, constancy)

(noun)

Nominative, neuter, singular of nityatva

nityatva - eternity, permanence, constancy

From nitya (eternal) + tva (suffix for abstract noun).

Note: Predicate nominative.

देवसद्मसु (devasadmasu) - in divine abodes, in temples

(noun)

Locative, neuter, plural of devasadman

devasadman - divine abode, temple, heaven

Compound deva (god) + sadman (abode).

Compound type : ṣaṣṭhī-tatpuruṣa (deva+sadman)

• deva – god, divine, celestial
  noun (masculine)
  From root div (to shine).
  Root: div (class 4)
• sadman – abode, dwelling, house
  noun (neuter)
  From root sad (to sit) + man suffix.
  Root: sad (class 1)

जगत् (jagat) - the world (world, universe, moving)

(noun)

Nominative, neuter, singular of jagat

jagat - moving, living; the world, universe (present participle of gam used as noun)

Present Active Participle

From root gam (to go) + śatṛ (at) suffix.

Root: gam (class 1)

Note: Subject of the simile.

जीर्णकुटीदीपः (jīrṇakuṭīdīpaḥ) - lamp of a dilapidated hut

(noun)

Nominative, masculine, singular of jīrṇakuṭīdīpa

jīrṇakuṭīdīpa - lamp in an old hut

Compound jīrṇa (dilapidated) + kuṭī (hut) + dīpa (lamp).

Compound type : ṣaṣṭhī-tatpuruṣa (jīrṇa+kuṭī+dīpa)

• jīrṇa – old, worn out, dilapidated, digested
  adjective
  Past Passive Participle
  From root jṝ (to wear out, to decay).
  Root: jṝ (class 9)
• kuṭī – hut, cottage
  noun (feminine)
• dīpa – lamp, light
  noun (masculine)
  From root dīp (to shine) + a suffix.
  Root: dīp (class 4)

Note: Predicate nominative for jagat (implied iva).

कूपोम्भस्तमसोः (kūpombhastamasoḥ) - in well-water and in darkness (of well-water and darkness; in well-water and darkness)

(noun)

Locative, neuter, dual of kūpombhastamas

kūpombhastamas - well-water and darkness

dvandva compound of kūpombhas (well-water) and tamas (darkness). kūpombhas is likely kūpa + umbhas (water).

Compound type : dvandva (kūpombhas+tamas)

• kūpombhas – well-water
  noun (neuter)
  Compound kūpa (well) + umbhas (water).
• tamas – darkness, gloom; ignorance; the quality of tamas
  noun (neuter)
  From root tam (to be dark)
  Root: tam (class 4)

Note: Indicates location where the 'great one' is found.

महान् (mahān) - a great entity (referring to a divine being or principle) (great, mighty, large)

(adjective)

Nominative, masculine, singular of mahat

mahat - great, large, mighty, important; great principle, cosmic intellect

From root mah (to be great)

Root: mah (class 1)

Note: Subject.