Manava Dharmashastra 11.115

11.115

anena vidhinā yas tu goghno gām anugacchati
sa gohatyākṛtaṃ pāpaṃ tribhir māsair vyapohati //

Let him not say (a word), if a cow eats (anything) in his own or another's house or field or on the threshing-floor, or if a calf drinks (milk).