Mimamsasutra 42.2.3

42.2.3

yasmingranthe sāmagāstṛtve tṛce sāmaikaikaṃ gāyanti, so'yamūhagrantho nityaḥ, na tu puruṣeṇa nirmitaḥ| kutaḥ| anadhyāyavarjanena, karturasmaraṇena, adhyāpakānāṃ vedatvaprasirḍīm̐tnślaṃṃ ca vedasāmanāmakayonigranthasadṛśatvāt| iti cet|
maivam| apauruṣeyatve vidhivaiyarthyaprasaṅgāt| "yadyonyāṃ, taduttarayorgāyati" iti vidhīyate| ayamarthaḥ- ’apauruṣeyatvena saṃpratipanne vedasāmanāmake granthe ’kayānaścitra ābhuvat’ ityetasyāṃ yonyāmekasyāmṛci yadvāmadevyanāmakaṃ sāmopadiṣṭam, tadevottarayoṛcoḥ- ’kastvā satyo madānām’- ’abhīṣuṇaḥ sakhīnām-’ ityanayordvitīya- tṛtīyayorgātavyam’- ityayaṃ vidhirūhagranthasya vedatve vyarthaḥ syāt| vedasāmavadadhyayanādeva tatsirḍhḍheḥ| uparitana ṛgdvaye sāmohasya pauruṣeyatve'pi sāmasvarūpasya tadādhārabhūtānāṃ tisṛṇāmṛcāṃ ca vedatvādanadhyāyā varjanīyāḥ| karturasmaraṇaṃ jīrṇakūpārāmādiṣviva cirakālavyavadhānādupapannam| asmaraṇamūlaivādhyāpakānāṃ vedatvaprarsiḍhḍhaḥ| yathā bahvṛcā adhyāpakā mahāvrataprayogapratipādakamāśvalāghananirmitaṃ kalpasūtramaraṇye'dhīyānāḥ pañcamāraṇyakamiti vedatvena vyavaharanti| na ca - tasyāpi vedatvamastu- iti vācyam| prathamāraṇyakena punaruktatvāt, arthavāda sāhityena brāhmaṇasādṛśyābhāvācca |
tasmāt- pañcamāraṇyakavadūhaḥ pauruṣeyaḥ| pauruṣeyasya ca nyāmūlatvādyatra vakṣyamāṇanyāyavirodhaḥ, tadapramāṇam|
(dvitīye- sāmna ṛksaṃskārakarmatādhikaraṇe sūtrāṇi 3-13)|
karma vā vidhilakṣaṇam ||

If it is argued: "The book of adaptation (Ūhagrantha), in which the Sāmaveda singers sing each single sāman across a triplet [of verses], is eternal, not composed by a human being. Why? Because of the avoidance of unpropitious days of study, the non-remembrance of an author, and the teachers' renown of its being the Veda, just like the archetype book (Yonigrantha) named Veda-sāman."—
It is not so; because, if it were not of human origin, an injunction would be rendered meaningless. It is enjoined: "Whatever [sāman] is on the basic verse, that he sings on the following two [verses]." The meaning of this is: 'The sāman named Vāmadevya that is taught on that single basic verse "By what manner of help was the wonderful [friend]..." in the book named Veda-sāman accepted to be of superhuman origin, that very same [sāman] must be sung on the following two verses, namely the second and third verses: "Who is the true [protector] among delights?" and "To us, O friends...".' This injunction would be purposeless if the book of adaptation were the Veda, since that [adaptation] would already be established merely by study, just like the Veda-sāman. Even though the adaptation of the sāman on the upper two verses is of human origin, the unpropitious days of study must be avoided because the nature of the sāman and the three verses that are its substrate are the Veda. The non-remembrance of an author is explicable by the intervention of a long period of time, just as in the case of dilapidated wells, gardens, and the like. The teachers' renown of its being the Veda is rooted merely in this non-remembrance. Just as the teachers of the Ṛgveda, studying in the forest the Kalpasūtra composed by Āśvalāyana which sets forth the performance of the Mahāvrata, refer to it as the Veda, calling it the 'Fifth Āraṇyaka'. Nor can it be said: "Let that too be the Veda," because it is redundant with the First Āraṇyaka, and because it lacks the resemblance to a Brāhmaṇa through conjunction with corroborative statements. Therefore, like the Fifth Āraṇyaka, the adaptation is of human origin. And since that which is of human origin has its basis in exegetical principle, wherever there is a contradiction with an exegetical principle to be stated later, that is not an authority.
(In the second topical section, demonstrating that the sāman is an action of refining the verse, sūtras 3–13:)
Or [the sāman is] an action, characterized by an injunction,