Mahabharata 13.75.14

एवं तस्याग्रे पूर्वमर्धं वदेत; गवां दाता विधिवत्पूर्वदृष्टम्प्रतिब्रूयाच्छेषमर्धं द्विजातिः; प्रतिगृह्णन्वै गोप्रदाने विधिज्ञः

evaṃ tasyāgre pūrvamardhaṃ vadeta; gavāṃ dātā vidhivatpūrvadṛṣṭampratibrūyāccheṣamardhaṃ dvijātiḥ; pratigṛhṇanvai gopradāne vidhijñaḥ

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