Bhagavad Gita · 4.18

कर्मण्यकर्म यः पश्येदकर्मणि च कर्म यः।स बुद्धिमान्मनुष्येषु स युक्तः कृत्स्नकर्मकृत्॥

karmaṇy akarma yaḥ paśhyed akarmaṇi cha karma yaḥ sa buddhimān manuṣhyeṣhu sa yuktaḥ kṛitsna-karma-kṛit

One who sees inaction in action and action in inaction is wise among human beings. Such a person is a yogi and has accomplished all actions.

— Bhagavad Gita 4.18

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