Ramayana 2.21.30

ऋषिणा च पितुर्वाक्यं कुर्वता व्रतचारिणा।गौर्हता जानता धर्मं कण्डुनाऽपि विपश्चिता।।2.21.30।।

ṛṣiṇā ca pitur vākyaṃ kurvatā vratacāriṇā | gaur hatā jānatā dharmaṃ kaṇḍunā ’pi vipaścitā || 2.21.30 ||

Even the learned sage Kandu—who knew dharma and lived by strict vows—killed a cow solely to carry out his father’s command.