Bhagavad Gita · 4.19

यस्य सर्वे समारम्भाः कामसङ्कल्पवर्जिताः।ज्ञानाग्निदग्धकर्माणं तमाहुः पण्डितं बुधाः॥

yasya sarve samārambhāḥ kāma-saṅkalpa-varjitāḥ jñānāgni-dagdha-karmāṇaṁ tam āhuḥ paṇḍitaṁ budhāḥ

One whose every undertaking is free from the desire for results, and whose actions are burnt in the fire of knowledge — such a person the wise call a paṇḍita (truly learned).

— Bhagavad Gita 4.19

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)