योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-79, verse-22

तत्पुराणेतिहासानां सर्वसंक्षयवादिनाम् ।
स्मृत्यादीनां सवेदानां वैयर्थ्यमुपजायते ॥ २२ ॥

tatpurāṇetihāsānāṃ sarvasaṃkṣayavādinām ,
smṛtyādīnāṃ savedānāṃ vaiyarthyamupajāyate 22

22. tat purāṇetihāsānām sarvasaṃkṣayavādinām
smṛtyādīnām savedānām vaiyarthyam upajāyate

22. tat purāṇetihāsānām sarvasaṃkṣayavādinām
smṛtyādīnām savedānām vaiyarthyam upajāyate

22. Then, if that is so, the Purāṇas and Itihāsas, which speak of universal dissolution, as well as the Smṛtis and even the Vedas, would all become meaningless and futile.

Words meanings summery:

• तत् (tat) - then, in that case (that, it)

• पुराणेतिहासानाम् (purāṇetihāsānām) - of the Purāṇas and Itihāsas

• सर्वसंक्षयवादिनाम् (sarvasaṁkṣayavādinām) - of those (texts) that speak of universal dissolution (of those proclaiming universal dissolution)

• स्मृत्यादीनाम् (smṛtyādīnām) - of the Smṛtis and other (traditional texts) (of the Smṛtis and others)

• सवेदानाम् (savedānām) - and even the Vedas (of the Vedas (with them), along with the Vedas)

• वैयर्थ्यम् (vaiyarthyam) - meaninglessness and futility (uselessness, futility, meaninglessness)

• उपजायते (upajāyate) - would arise, would become (arises, comes into being, is born)

Words meanings and morphology

तत् (tat) - then, in that case (that, it)

(indeclinable)

Note: Used adverbially to mean 'then' or 'therefore'.

पुराणेतिहासानाम् (purāṇetihāsānām) - of the Purāṇas and Itihāsas

(noun)

Genitive, masculine, plural of purāṇetihāsa

purāṇetihāsa - Purāṇas and Itihāsas (epics and ancient narratives)

Dvandva compound.

Compound type : dvandva (purāṇa+itihāsa)

• purāṇa – ancient, old; a class of sacred texts
  noun (neuter)
  From purā (formerly).
• itihāsa – history, legend, epic
  noun (masculine)
  iti ha āsa (thus it was).

Note: Specifies the texts that would become useless.

सर्वसंक्षयवादिनाम् (sarvasaṁkṣayavādinām) - of those (texts) that speak of universal dissolution (of those proclaiming universal dissolution)

(adjective)

Genitive, masculine, plural of sarvasaṃkṣayavādin

sarvasaṁkṣayavādin - proclaiming universal dissolution, advocating complete destruction

From sarvasaṃkṣaya (universal dissolution) + -vādin (speaker, advocate).

Compound type : tatpurusha (sarvasaṃkṣaya+vādin)

• sarvasaṃkṣaya – universal dissolution, total destruction
  noun (masculine)
  Compound of sarva (all) and saṃkṣaya (dissolution).
• vādin – speaker, advocate, proponent
  noun (masculine)
  agent noun
  From root vad (to speak) + suffix -in.
  Root: vad (class 1)

Note: Qualifies purāṇetihāsānām and smṛtyādīnām.

स्मृत्यादीनाम् (smṛtyādīnām) - of the Smṛtis and other (traditional texts) (of the Smṛtis and others)

(noun)

Genitive, masculine, plural of smṛtyādi

smṛtyādi - Smṛtis etc. (traditional texts)

Compound.

Compound type : tatpurusha (smṛti+ādi)

• smṛti – remembrance, tradition, sacred tradition, Smṛti texts
  noun (feminine)
  From root smṛ (to remember).
  Root: smṛ (class 1)
• ādi – beginning, commencement, first, etcetera
  noun (masculine)

Note: Masculine plural genitive, referring to texts.

सवेदानाम् (savedānām) - and even the Vedas (of the Vedas (with them), along with the Vedas)

(adjective)

Genitive, masculine, plural of saveda

saveda - having the Vedas, together with the Vedas

Bahuvrīhi compound or prefix sa- (with) + veda.

Compound type : bahuvrīhi (sa+veda)

• sa – with, together with
  prefix
  Prefix for forming bahuvrīhi compounds.
• veda – knowledge, sacred knowledge, the Vedas (a collection of hymns and sacred texts)
  noun (masculine)
  From root vid (to know).
  Root: vid (class 2)

Note: Agrees with purāṇetihāsānām and smṛtyādīnām.

वैयर्थ्यम् (vaiyarthyam) - meaninglessness and futility (uselessness, futility, meaninglessness)

(noun)

Nominative, neuter, singular of vaiyarthya

vaiyarthya - uselessness, futility, unprofitableness

From vyartha (useless) + suffix -ya.

Note: Subject of upajāyate.

उपजायते (upajāyate) - would arise, would become (arises, comes into being, is born)

(verb)

3rd person , singular, middle, present indicative (laṭ) of jan

Present middle indicative 3rd person singular

From upa + root jan.

Prefix: upa

Root: jan (class 4)

Note: The implied sense is conditional ("would arise") due to cet in the previous verse.