Shatapatha Brahmana 4.5.2.10

4.5.2.10

yasyai te yajñiyo garbha iti | ayajñiyā vai garbhāstametadbrahmaṇaiva yajuṣā yajñiyaṃ karoti yasyai yonihiraṇyayītyado vā etasyai yoniṃ vicindanti yadado niṣkarṣantyamṛtamāyurhiraṇyaṃ tāmevāsyā etadamṛtāṃ yoniṃ karotyaṅgānyahrutā yasya tam mātrā samajīgamaṃ svāheti yadi pumāntsyādyadyu strī syādaṅgānyahrutā yasyai tām mātrā samajīgamaṃ svāheti yadyu avijñāto garbho bhavati puṃskṛtyaiva juhuyātpumāṃso hi garbhā aṅgānyahrutā yasya tam mātrā samajīgamaṃ svāhetyado vā etam mātrā viṣvañcaṃ kurvanti yadado niṣkarṣanti tametadbrahmaṇaiva yajuṣā samardhya madhyato yajñasya punarmātrā saṅgamayati

With (Vâg. S. VIII, 29), 'Thou whose fruit is fit for sacrifice,'--for embryos are unfit for sacrifice: this one he thus makes fit for sacrifice by means of the Brahman, the Yagus;--'thou who hast a golden womb,'--for on that former occasion, they rend the womb when they tear out (the embryo); and gold means immortal life; he thus makes that womb of her (the cow) immortal;--'Him whose limbs are unbroken, I have brought together with his mother, Hail!' Thus, if it be a male (embryo); but if it be a female one, with, 'Her whose limbs are unbroken, I have brought together with her mother, Hail!' And, if it be an indistinguishable embryo, let him offer in making it male, since embryos (garbha, masc.) are male, 'Him whose limbs are unbroken, I have brought together with his mother, Hail!' For on that former occasion, when they tear out (the embryo) they separate it from its mother: now, having rendered it successful by means of the Brahman, the Yagus, he brings it again together with its mother in the midst of the sacrifice.