वाल्मीकि-रामायणम् vālmīki-rāmāyaṇam - book-1, chapter-29, verse-5

तौ तु तद्वचनं श्रुत्वा राजपुत्रौ यशस्विनौ ।
अनिद्रौ षडहोरात्रं तपोवनमरक्षताम् ॥५॥

5. tau tu tadvacanaṃ śrutvā rājaputrau yaśasvinau ,
anidrau ṣaḍahorātraṃ tapovanamarakṣatām.

5. tau tu tat vacanam śrutvā rājaputrau yaśasvinau
anidrau ṣaḍahorātrām tapovanam arakṣatām

5. tu tau yaśasvinau rājaputrau tat vacanam śrutvā
anidrau ṣaḍahorātrām tapovanam arakṣatām

5. Those two glorious princes, having heard his words, protected the hermitage for six days and nights without sleeping.

Words meanings summery:

• तौ (tau) - Rama and Lakshmana (those two)

• तु (tu) - indeed, but (but, indeed, yet, on the other hand)

• तत् (tat) - his (Vishvamitra's) (that, his)

• वचनम् (vacanam) - words, instruction (word, speech, saying)

• श्रुत्वा (śrutvā) - having heard

• राजपुत्रौ (rājaputrau) - Rama and Lakshmana, the two princes (two princes)

• यशस्विनौ (yaśasvinau) - glorious, famous, illustrious

• अनिद्रौ (anidrau) - sleepless, without sleep

• षडहोरात्राम् (ṣaḍahorātrām) - for six days and nights

• तपोवनम् (tapovanam) - the hermitage where Vishvamitra performed his tapas (penance) (hermitage, forest of penance)

• अरक्षताम् (arakṣatām) - they two protected

Words meanings and morphology

तौ (tau) - Rama and Lakshmana (those two)

(pronoun)

Nominative, masculine, dual of tad

tad - that, those

Note: Nominative dual masculine of tad

तु (tu) - indeed, but (but, indeed, yet, on the other hand)

(indeclinable)

तत् (tat) - his (Vishvamitra's) (that, his)

(pronoun)

Accusative, neuter, singular of tad

tad - that, those

Note: Accusative singular neuter of tad, modifying vacanam. Implies Vishvamitra's words from context.

वचनम् (vacanam) - words, instruction (word, speech, saying)

(noun)

Accusative, neuter, singular of vacana

vacana - word, speech, saying, instruction; declaration

From √vac (to speak)

Root: vac (class 2)

Note: Accusative singular of vacana

श्रुत्वा (śrutvā) - having heard

(indeclinable)

Absolutive (Gerund)

Absolutive of √śru (to hear)

Root: śru (class 5)

राजपुत्रौ (rājaputrau) - Rama and Lakshmana, the two princes (two princes)

(noun)

Nominative, masculine, dual of rājaputra

rājaputra - son of a king, prince

Compound type : tatpuruṣa (rājan+putra)

• rājan – king, ruler
  noun (masculine)
• putra – son, child
  noun (masculine)

Note: Nominative dual of rājaputra

यशस्विनौ (yaśasvinau) - glorious, famous, illustrious

(adjective)

Nominative, masculine, dual of yaśasvin

yaśasvin - famous, glorious, illustrious, renowned

From yaśas (fame) + -vin (possessive suffix)

Note: Nominative dual masculine of yaśasvin, agreeing with rājaputrau

अनिद्रौ (anidrau) - sleepless, without sleep

(adjective)

Nominative, masculine, dual of anidra

anidra - sleepless, awake, without sleep

Compound type : bahuvrīhi (a+nidra)

• a – not, un-
  indeclinable
• nidra – sleep, slumber
  noun (feminine)

Note: Nominative dual masculine of anidra, agreeing with rājaputrau, implies a state.

षडहोरात्राम् (ṣaḍahorātrām) - for six days and nights

(noun)

Accusative, neuter, singular of ṣaḍahorātra

ṣaḍahorātra - a period of six days and nights

Compound type : dvigu (ṣaṣ+ahorātra)

• ṣaṣ – six
  numeral
• ahorātra – day and night
  noun (neuter)

Note: Accusative singular of ṣaḍahorātra, indicating duration.

तपोवनम् (tapovanam) - the hermitage where Vishvamitra performed his tapas (penance) (hermitage, forest of penance)

(noun)

Accusative, neuter, singular of tapovana

tapovana - hermitage, forest for practicing asceticism or penance

Compound type : tatpuruṣa (tapas+vana)

• tapas – austerity, penance, heat
  noun (neuter)
• vana – forest, wood, grove
  noun (neuter)

Note: Accusative singular of tapovana

अरक्षताम् (arakṣatām) - they two protected

(verb)

3rd person , dual, active, imperfect past (laṅ) of rakṣ

Root: rakṣ (class 1)

Note: Third person dual imperfect active of √rakṣ (1st class)