Shatapatha Brahmana 3.3.1.16

3.3.1.16

sā syādapravītā | vāgvā eṣā nidāneta yatsomakrayaṇyayātayāmnī vā iyaṃ vāgayātayāmnyapravītā tasmādapravītā syātsā syādavaṇḍākūṭākāṇākarṇālakṣitāsaptaśaphā sā hyekarūpaikarūpā hīyaṃ vāk

Let it be one that is not impregnated. For that Soma-cow is in reality Vâk, and this Vâk (speech) is of unimpaired vigour; and of unimpaired vigour is one not (yet) impregnated: let it therefore be one not impregnated. Let it be one that is neither tailless, nor hornless, nor one-eyed, nor ear-less, nor specially marked, nor seven-hoofed;--for such a one is uniform, and uniform is this speech.