Jaiminīya Upaniṣad Brāhmaṇa 3.3.13

3.3.13

atha hainaṃ vasiṣṭha upaniṣasāda gaur etad uktham iti
tad etad annam eva
annaṃ hi gauḥ /

Then Vasiṣṭha approached him [saying], "This uktha is the cow (go)."
That is just food;
for the cow is food.