महाभारतः mahābhārataḥ - book-12, chapter-159, verse-14

इष्टिं वैश्वानरीं नित्यं निर्वपेदब्दपर्यये ।
अविकल्पः पुराधर्मो धर्मवादैस्तु केवलम् ॥१४॥

14. iṣṭiṁ vaiśvānarīṁ nityaṁ nirvapedabdaparyaye ,
avikalpaḥ purādharmo dharmavādaistu kevalam.

14. iṣṭim vaiśvānarīm nityam nirvapet abdaparyaye
avikalpaḥ purādharmaḥ dharmavādaiḥ tu kevalam

14. abdaparyaye nityam vaiśvānarīm
iṣṭim nirvapet (yadā) purā (hi)
dharmaḥ avikalpaḥ (āsīt) (idānim)
tu kevalam dharmavādaiḥ (bhavati)

14. One should regularly perform the Vaiśvānara (universal fire) sacrifice at the turn of the year. The sacred duty (dharma) of ancient times was without alternative; but now it is merely subject to discussions on (dharma).

Words meanings summery:

• इष्टिम् (iṣṭim) - a Vedic sacrifice (a sacrifice, an offering, a desire)

• वैश्वानरीम् (vaiśvānarīm) - related to Agni (fire god) in its universal aspect (related to Vaiśvānara, universal, belonging to all men)

• नित्यम् (nityam) - regularly, annually (always, constantly, regularly, eternally)

• निर्वपेत् (nirvapet) - one should perform (the sacrifice) (one should offer, one should perform, one should pour out)

• अब्दपर्यये (abdaparyaye) - annually, at the close of the year (at the turn of the year, at the end of the year, at the completion of the year)

• अविकल्पः (avikalpaḥ) - without alternative interpretations or disputes (without option, definite, unchanging, unwavering)

• पुराधर्मः (purādharmaḥ) - the sacred duty (dharma) as it was in ancient times (ancient (dharma), former (dharma), the (dharma) of old)

• धर्मवादैः (dharmavādaiḥ) - solely by discussions and interpretations regarding sacred duty (dharma) (by arguments about (dharma), by discussions of (dharma), by doctrines of (dharma))

• तु (tu) - but, introducing a contrast (but, however, indeed, on the other hand)

• केवलम् (kevalam) - only, exclusively (merely, only, solely, exclusively, entire)

Words meanings and morphology

इष्टिम् (iṣṭim) - a Vedic sacrifice (a sacrifice, an offering, a desire)

(noun)

Accusative, feminine, singular of iṣṭi

iṣṭi - a sacrifice, an offering, worship, desire, wish

Derived from root yaj (to sacrifice)

Root: yaj (class 1)

वैश्वानरीम् (vaiśvānarīm) - related to Agni (fire god) in its universal aspect (related to Vaiśvānara, universal, belonging to all men)

(adjective)

Accusative, feminine, singular of vaiśvānara

vaiśvānara - relating to all men, universal, omnipresent, (as noun) Agni, the fire god in his universal aspect

Derived from viśvānara (all men)

Note: Agrees with iṣṭim.

नित्यम् (nityam) - regularly, annually (always, constantly, regularly, eternally)

(indeclinable)

Note: Used adverbially here.

निर्वपेत् (nirvapet) - one should perform (the sacrifice) (one should offer, one should perform, one should pour out)

(verb)

3rd person , singular, active, optative (vidhiliṅ) of nirvap

With prefix nir-

Prefix: nir

Root: vap (class 1)

Note: Expresses prescription or recommendation.

अब्दपर्यये (abdaparyaye) - annually, at the close of the year (at the turn of the year, at the end of the year, at the completion of the year)

(noun)

Locative, masculine, singular of abdaparyaya

abdaparyaya - the close or turn of the year, annual cycle

Tatpuruṣa compound

Compound type : tatpuruṣa (abda+paryaya)

• abda – year, cloud
  noun (masculine)
• paryaya – turn, change, succession, end, close
  noun (masculine)
  Derived from i (to go) with pari- + aya
  Prefix: pari
  Root: i (class 2)

अविकल्पः (avikalpaḥ) - without alternative interpretations or disputes (without option, definite, unchanging, unwavering)

(adjective)

Nominative, masculine, singular of avikalpa

avikalpa - without alternative, definite, firm, unwavering, without doubt

Negative compound (nañ-tatpuruṣa) of vikalpa (option, doubt)

Compound type : nañ-tatpuruṣa (a+vikalpa)

• a – not, un-, non-
  indeclinable
  Negative prefix
• vikalpa – option, alternative, doubt, uncertainty
  noun (masculine)
  Derived from root kḷp (to arrange) with vi-
  Prefix: vi
  Root: kḷp (class 1)

Note: Agrees with dharmaḥ.

पुराधर्मः (purādharmaḥ) - the sacred duty (dharma) as it was in ancient times (ancient (dharma), former (dharma), the (dharma) of old)

(noun)

Nominative, masculine, singular of purādharma

purādharma - ancient dharma, former dharma

Adverbial compound (avyayībhāva) or a descriptive compound. Here, purā acts as an adjective 'old' for dharma.

Compound type : tatpuruṣa (purā+dharma)

• purā – formerly, anciently, in former times
  indeclinable
• dharma – constitution, natural law, intrinsic nature, sacred duty, righteousness, law, virtue
  noun (masculine)
  Derived from root dhṛ (to uphold, sustain)
  Root: dhṛ (class 1)

Note: Refers to the sacred law or duty.

धर्मवादैः (dharmavādaiḥ) - solely by discussions and interpretations regarding sacred duty (dharma) (by arguments about (dharma), by discussions of (dharma), by doctrines of (dharma))

(noun)

Instrumental, masculine, plural of dharmavāda

dharmavāda - discussion of dharma, doctrine of dharma, argument about dharma

Tatpuruṣa compound

Compound type : tatpuruṣa (dharma+vāda)

• dharma – constitution, natural law, intrinsic nature, sacred duty, righteousness, law, virtue
  noun (masculine)
  Derived from root dhṛ (to uphold, sustain)
  Root: dhṛ (class 1)
• vāda – speech, discourse, discussion, argument, doctrine
  noun (masculine)
  Derived from root vad (to speak)
  Root: vad (class 1)

तु (tu) - but, introducing a contrast (but, however, indeed, on the other hand)

(indeclinable)

Note: Conjunction.

केवलम् (kevalam) - only, exclusively (merely, only, solely, exclusively, entire)

(indeclinable)

Note: Used adverbially here.