Bhagavad Gita 4.19
यस्य सर्वे समारम्भाः कामसङ्कल्पवर्जिताः। ज्ञानाग्निदग्धकर्माणं तमाहुः पण्डितं बुधाः।।4.19।।
yasya sarve samārambhāḥ kāmasaṅkalpavarjitāḥ| jñānāgnidagdhakarmāṇaṃ tamāhuḥ paṇḍitaṃ budhāḥ||4.19||
yasya sarve samarambhah kamasankalpavarjitah jnanagnidagdhakarmanam tamahuh panditam budhah4.19
Meaning
One whose every undertaking is free from desire and selfish purpose, and whose actions are purified by the fire of knowledge — such a person is called a sage by the wise.
जिसके समस्त कार्य कामना और संकल्प से रहित हैं, ऐसे उस ज्ञानरूप अग्नि के द्वारा भस्म हुए कर्मों वाले पुरुष को ज्ञानीजन पण्डित कहते हैं।
This is verse 19 of 42 in Chapter 4 (Jnana Karma Sanyasa Yoga) of the Bhagavad Gita.