Mahabharata 12.199.18

ऋचामादिस्तथा साम्नां यजुषामादिरुच्यतेअन्तश्चादिमतां दृष्टो न चादिर्ब्रह्मणः स्मृतः

ṛcāmādistathā sāmnāṃ yajuṣāmādirucyateantaścādimatāṃ dṛṣṭo na cādirbrahmaṇaḥ smṛtaḥ

Our plain-language meaning of this verse is waiting for scholar review.