योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-44, verse-8

आशौरिदर्शनं तस्मिंस्तपोर्थं सरसि द्विजः ।
आकण्ठमम्बुनिर्मग्नः प्रावृट्पद्म इवाविशत् ॥ ८ ॥

āśauridarśanaṃ tasmiṃstaporthaṃ sarasi dvijaḥ ,
ākaṇṭhamambunirmagnaḥ prāvṛṭpadma ivāviśat 8

8. āśauridarśanam tasmin tapasartham sarasi dvijaḥ
ākaṇṭham ambunirmagnaḥ prāvṛṭpadmaḥ iva āviśat

8. dvijaḥ āśauridarśanam tapasartham tasmin sarasi
ākaṇṭham ambunirmagnaḥ prāvṛṭpadmaḥ iva āviśat

8. For the purpose of his spiritual austerities (tapas), that Brahmin (dvija) entered that lake, remaining immersed up to his neck in the water until he received a vision of Śauri, just like a lotus of the rainy season.

Words meanings summery:

• आशौरिदर्शनम् (āśauridarśanam) - until the sight of Śauri, up to the vision of Śauri

• तस्मिन् (tasmin) - in that

• तपसर्थम् (tapasartham) - for the purpose of austerity (tapas)

• सरसि (sarasi) - in the lake, in the pond

• द्विजः (dvijaḥ) - the Brahmin, the twice-born

• आकण्ठम् (ākaṇṭham) - up to the neck, neck-deep

• अम्बुनिर्मग्नः (ambunirmagnaḥ) - immersed in water, submerged in water

• प्रावृट्पद्मः (prāvṛṭpadmaḥ) - a lotus of the rainy season, a monsoon lotus

• इव (iva) - like, as, as if

• आविशत् (āviśat) - he entered, he commenced, he devoted himself

Words meanings and morphology

आशौरिदर्शनम् (āśauridarśanam) - until the sight of Śauri, up to the vision of Śauri

(indeclinable)

Compound noun used adverbially, indicating a limit (ā-).

Compound type : tatpuruṣa (śauri+darśana)

• śauri – Śauri (an epithet of Krishna/Vishnu, son of Śūra)
  proper noun (masculine)
• darśana – sight, vision, seeing, audience
  noun (neuter)
  Derived from root DṚŚ (to see).
  Root: dṛś (class 1)

तस्मिन् (tasmin) - in that

(pronoun)

Locative, neuter, singular of tad

tad - that, he, she, it

Demonstrative pronoun.

तपसर्थम् (tapasartham) - for the purpose of austerity (tapas)

(indeclinable)

Compound noun in accusative, used adverbially.

Compound type : tatpuruṣa (tapas+artha)

• tapas – penance, austerity, spiritual fervor
  noun (neuter)
  Root: tap (class 1)
• artha – purpose, meaning, wealth, for the sake of
  noun (masculine/neuter)

सरसि (sarasi) - in the lake, in the pond

(noun)

Locative, neuter, singular of saras

saras - lake, pond, pool

s-stem noun.

Root: sṛ (class 1)

द्विजः (dvijaḥ) - the Brahmin, the twice-born

(noun)

Nominative, masculine, singular of dvija

dvija - twice-born (Brahmin, Kshatriya, Vaishya), a Brahmin, a bird, a tooth

Compound: dvi (two) + ja (born).

Compound type : tatpuruṣa (dvi+ja)

• dvi – two
  numeral
• ja – born, produced from
  adjective
  Derived from root JAN (to be born).
  Root: jan (class 4)

आकण्ठम् (ākaṇṭham) - up to the neck, neck-deep

(indeclinable)

Compound used adverbially.

Compound type : avyayībhāva (ā+kaṇṭha)

• ā – up to, until, towards
  indeclinable/prefix
• kaṇṭha – neck, throat
  noun (masculine)

Note: Adverb modifying the immersion.

अम्बुनिर्मग्नः (ambunirmagnaḥ) - immersed in water, submerged in water

(adjective)

Nominative, masculine, singular of ambunirmagna

ambunirmagna - immersed in water, submerged in water

Compound adjective.

Compound type : tatpuruṣa (ambu+nirmagna)

• ambu – water
  noun (neuter)
  Root: amb (class 1)
• nirmagna – immersed, submerged, plunged into
  adjective
  Past Passive Participle
  Derived from root MAJJ (to sink, immerse) with prefix NIR-.
  Prefix: nir
  Root: majj (class 6)

Note: Describes dvijaḥ.

प्रावृट्पद्मः (prāvṛṭpadmaḥ) - a lotus of the rainy season, a monsoon lotus

(noun)

Nominative, masculine, singular of prāvṛṭpadma

prāvṛṭpadma - a lotus of the rainy season

Compound noun.

Compound type : tatpuruṣa (prāvṛṭ+padma)

• prāvṛṭ – rainy season, monsoon
  noun (feminine)
• padma – lotus
  noun (masculine/neuter)
  Root: pad

इव (iva) - like, as, as if

(indeclinable)

Particle of comparison.

आविशत् (āviśat) - he entered, he commenced, he devoted himself

(verb)

3rd person , singular, active, past imperfect (laṅ) of āviś

Imperfect tense, Parasmaipada, 3rd person singular

Derived from root VIŚ (to enter) with prefix Ā-.

Prefix: ā

Root: viś (class 6)