वाल्मीकि-रामायणम् vālmīki-rāmāyaṇam - book-1, chapter-13, verse-33

त्र्यहो ऽश्वमेधः संख्यातः कल्पसूत्रेण ब्राह्मणैः ।
चतुष्टोममहस्तस्य प्रथमं परिकल्पितम् ॥३३॥

33. tryaho'śvamedhaḥ saṃkhyātaḥ kalpasūtreṇa brāhmaṇaiḥ ,
catuṣṭomamahastasya prathamaṃ parikalpitam.

33. tryahaḥ aśvamedhaḥ saṃkhyātaḥ kalpasūtreṇa brāhmaṇaiḥ
catuṣṭomam ahaḥ tasya prathamam parikalpitam

33. kalpasūtreṇa brāhmaṇaiḥ aśvamedhaḥ tryahaḥ saṃkhyātaḥ
tasya prathamam catuṣṭomam ahaḥ parikalpitam

33. The Aśvamedha (yajña) is reckoned as a three-day (tryaha) event by the Brahmins according to the Kalpasūtra. Its first (day) is prescribed as the Catustoma day.

Words meanings summery:

• त्र्यहः (tryahaḥ) - three-day, lasting three days

• अश्वमेधः (aśvamedhaḥ) - horse sacrifice (Aśvamedha)

• संख्यातः (saṁkhyātaḥ) - counted, reckoned, described

• कल्पसूत्रेण (kalpasūtreṇa) - by the Kalpasūtra

• ब्राह्मणैः (brāhmaṇaiḥ) - by the Brahmins

• चतुष्टोमम् (catuṣṭomam) - the Catustoma (a type of Soma sacrifice)

• अहः (ahaḥ) - day

• तस्य (tasya) - of it, its

• प्रथमम् (prathamam) - the first

• परिकल्पितम् (parikalpitam) - ordained, arranged, prescribed

Words meanings and morphology

त्र्यहः (tryahaḥ) - three-day, lasting three days

(adjective)

Nominative, masculine, singular of tryaha

tryaha - three-day, of three days

Compound type : dvigu (tri+ahas)

• tri – three
  numeral
• ahas – day
  noun (masculine)

Note: Agrees with 'aśvamedhaḥ'

अश्वमेधः (aśvamedhaḥ) - horse sacrifice (Aśvamedha)

(noun)

Nominative, masculine, singular of aśvamedha

aśvamedha - horse sacrifice, a grand Vedic ritual (yajña)

Compound type : tatpuruṣa (aśva+medha)

• aśva – horse
  noun (masculine)
• medha – sacrifice, oblation
  noun (masculine)

संख्यातः (saṁkhyātaḥ) - counted, reckoned, described

(verbal derivative)

Note: Agrees with 'aśvamedhaḥ'

कल्पसूत्रेण (kalpasūtreṇa) - by the Kalpasūtra

(noun)

Instrumental, neuter, singular of kalpasūtra

kalpasūtra - a class of Sūtras prescribing ritual procedures

Compound type : tatpuruṣa (kalpa+sūtra)

• kalpa – rule, ritual, sacred precept
  noun (masculine)
• sūtra – thread, string, aphorism, rule, treatise
  noun (neuter)

ब्राह्मणैः (brāhmaṇaiḥ) - by the Brahmins

(noun)

Instrumental, masculine, plural of brāhmaṇa

brāhmaṇa - a Brahmin, a member of the priestly class

चतुष्टोमम् (catuṣṭomam) - the Catustoma (a type of Soma sacrifice)

(noun)

Nominative, masculine, singular of catuṣṭoma

catuṣṭoma - a particular Soma sacrifice, one of the seven Soma-institutions

Note: This form can be masculine nominative singular, or neuter nominative/accusative singular. Here interpreted as nominative describing 'ahaḥ'.

अहः (ahaḥ) - day

(noun)

Nominative, masculine, singular of ahas

ahas - day, daylight

Note: Can also be neuter in some contexts, but typically masculine when independent. Here, it functions in apposition to 'prathamam'.

तस्य (tasya) - of it, its

(pronoun)

Genitive, masculine, singular of tad

tad - that, it, its

Note: Refers to 'aśvamedha'.

प्रथमम् (prathamam) - the first

(adjective)

Nominative, neuter, singular of prathama

prathama - first, foremost, primary

Note: Functions as a substantive referring to 'the first (part/day)' and is the subject of 'parikalpitam'.

परिकल्पितम् (parikalpitam) - ordained, arranged, prescribed

(verbal derivative)

Note: Agrees with 'prathamam'