Shatapatha Brahmana 11.7.2.2

11.7.2.2

tadāhuḥ iṣṭiḥ paśubandhā3 mahāyajñā3 iti mahāyajña iti ha brūyādiṣṭiṃ vai tarhi paśubandhamakarvyenamakṛkṣathā ityenam brūyāt

Concerning this they ask, 'Is the animal sacrifice an ishti or a great (Soma-) sacrifice?'--'A great sacrifice,' let him say; 'for in that (other) case thou hast made the animal sacrifice an ishti, and shattered it.' Thus he should say to him.