Yāska's Nirukta 2.4

2.4

āha-kaḥ punareteṣu viśeṣo yenaita eva jñāpayantīti ? || ucyate-yasmādete gavādyaḥ "chandobhyaḥ samāhṛtyasamāhṛtya samāmnātāḥ" || chandāṃsi mantrāḥ tebhya upalakṣitasāmarthyāḥ samāhṛtya granthīkṛtā ityarthaḥ || āha-'kasmātpunaretāvanta eva granthīkṛtāḥ' iti|| ucyateito yasmādetaireva chandasyavasthitairabhiniviṣṭadhiyāmapi medhāvināṃ tapasvināṃ lakṣaṇaviniyogārṣacchandodaivatanidānavidāmapi satāṃ mantrārthaparijñānāyodyamabhaṅgaḥ kriyate, duṣparijñānatvāt teṣām, eteṣu parijñāteṣu apratibandhena śakyate mantrārthaḥ parijñātumiti ata ucyate ta eva jñāpakā bhavantīti | ataścaita evonnītasāmarthyāḥ samāhṛtyasamāhṛtya samāmnātā iti samāmnānamātrameva darśayati | prakaraṇagatāśca nityā evaita iti gamyate |
"te nigantava eva santo nigamanānnighaṇṭava ucyanta ityaupamanyavaḥ” | udāhṛtāḥ samāmnātāḥ nirvacanaprasaṅgato nirucyante | ya ete samāmnātā gavādyaḥ ta ete mantrārthanigamayitṛtvādubhaye'pi nigantavaḥ santo nigamanādvaitaunighaṇṭava ucyanta ityaupamanyavaḥ | ityevamarthanigamayitṛtvāmnigantava ete sampannāḥ santo'tiparokṣavṛttinā śabdena gakārasthāne ghakāraṃ kṛtvā takārasthāne ca ṭakāraṃ kṛtvā varṇavyāpattyādilakṣaṇam | athāpyādiviparyaya ityevamādi tadetatparokṣātiparokṣavṛttiṣu yathāsambhavaṃ draṣṭavyam || trividhā hi śabdavyavasthā-pratyakṣavṛttayaḥ, parokṣavṛttayaḥ, atiparokṣavṛttayaśca | tatroktakriyāḥ pratyakṣavṛttayaḥ, antarlīnakriyāḥ parokṣavṛttayaḥ, atiparokṣavṛttiṣu śabdeṣu nirvacanānyupāyaḥ | tasmātparokṣavṛttitāmāpādya pratyakṣavṛttinā śabdena nirvaktavyāḥ | tadyathā-nighaṇṭava ityatiparokṣavṛttiḥ nigantava iti parokṣavṛttiḥ, nigamayitāra iti pratyakṣavṛttiḥ | yasmānnigamayitāra ete nigantava iti nighaṇṭava ityucyante | uktañca-
vakṣyati cāyamapi-varṇaviparyayavarṇavyāpattilakṣaṇam | ta ete nigantavaḥ santo nighaṇṭava ucyante ityevamatimarokṣavṛttayo nirvaktavyāḥ|| prāyeṇa coṇādiṣu parokṣavṛttayaḥ śabdāścintyante | tatra teṣāṃ lakṣaṇamṛgekṣitavyam | yeṣāmapi lakṣaṇaṃ nāsti, teṣāmapi tatra kalpyam | aparisamāptā guṇādaya iti lakṣaṇavidaḥ pratijānate | sarvathāpi lakṣaṇāsambhave pṛṣodarādipāṭhasiddhireva draṣṭavyā | tatra hi yathādhyayanameva śabdāḥ sādhīyāṃso bhavantyabhivyāhārānabhighātāyeti
hi lakṣaṇavido manyante ityaupamanyavaḥ | evamaupamanyava ācāryo manyata iti vākyaśeṣaḥ | uparatamanyurupamanyustasyāpatyamaupamanyavaḥ | kīrttiprathanārthamaupamanyavagrahaṇam|