Manava Dharmashastra 2.29.2

2.29.2

yato na samākhyayā puruṣasya niyataḥ sambandhaḥ gotrapravaravat | yaiva śākhā yenādhītā sa eva tayā samākhyāyate 'kaṭho bahvṛca' iti na cādhyayane niyamo'styaneneyaṃ śākhā'dhyetavyeti | anekaśākhādhyayanamapyasti, vedānadhītyeti | tatra trivedādhyāyinaḥ sarve vyapadeśāḥ pravarttante | ke'pyūcuḥ kauthumāḥ kaṭhā bahvṛca iti tatrāvaśyaṃ vikalpa āstheyaḥ | ekaśākhādhyāyinastu yadgṛhyaṃ yayā śākhayā samākhyāyate taduktameva tasya yuktaṃ kartum | eṣa hi taduktameva śaknoti kartuṃ tacchākhāmantrā eva tenādhītāḥ, śaknoti tānprayoktum | tameva vā vṛtaṃ veda | "vedane ca karmānuṣṭhānārthaṃ vedādhyayanaṃ yena tāvato mantrānkarmopayogino'dhyeyyata iti |" ucyate | svādhyāyavidhivaśena vedādhyayanam | anadhītavedasya nādhikāraḥ | na ca karmaprayuktamadhyayanam | ata iyaṃ samākhyā mantraviśeṣaviniyoganimittaiva 'kaṭhānāṃ gṛhya', 'vājasaneyināṃ gṛhyamiti' | yasyāṃ śākhāyāṃ ye mantrā adhītāste yatra bāhulyena viniyuktāstadgṛhyaṃ tathā samākhyāyate | pramāṇaṃ gṛhyasmṛtiḥ | sā kaṭhānāmiyamiti vyapadiśyamānā bahvṛcānāmapi svārthāvagamanaṃ karotyeva | kartavyatā vedasya svārthe smṛtīnāṃ ca | avagatāyāṃ ca kartavyatāyāṃ kartṛviśeṣāśravaṇe svādhikāro na syādyathā ca tanūnapāti prayāje vasiṣṭhānāṃ, niṣedhādvā patitam | na ceha dvayamapyasti | na ca śakyaṃ kalpayituṃ na hi kaṭhānāṃ bahvṛcyaṃ pramāṇaṃ, bahvṛcānāṃ vā kāṭhakam | yato ya eva kaṭhaḥ sa evākaṭho'sati tacchākhādhyayane | gotraṃ tu niyatamityasamānaḥ | eṣa evārthaḥ 'svasūtraṃ yaḥ parityajya parasūtreṇa vartata' iti |