Manava Dharmashastra 2.17

2.17

uktāni dharme pramāṇāni | virodhe ca vikalpo'bhihitaḥ | adhikāriṇaśca sāmānyenoktāḥ | idānīṃ yeṣu yogyatayā dharmo'nuṣṭheyatāmāpadyate te deśā varṇyante | sarasvatī nāma nadī | aparā dṛṣadvatī | tayornadyorya dantaraṃ madhyaṃ taṃ deśaṃ brahmāvarta ityanayā saṃjñayā pracakṣate vyavaharanti śiṣṭāḥ |
devagrahaṇāmavadhyavadhimatoḥ stutyartham | devaiḥ sa nirmito'taḥ sarvebhyo deśebhyaḥ pāvanatara iti |

Now no Smṛti or Practice, that is prompted by a perceptible motive, can ever be regarded as authoritative. Says the revered Bhatta (Kumārila)—‘That Smṛti, which is contrary to the Veda, or deprecated, and which serves a visible purpose, and is prompted by perceptible motives, can never he based upon the Veda.’