BG 4.18
कर्मण्यकर्म यः पश्येदकर्मणि च कर्म यः। स बुद्धिमान् मनुष्येषु स युक्तः कृत्स्नकर्मकृत्
karmaṇyakarma yaḥ paśhyed akarmaṇi cha karma yaḥ sa buddhimān manuṣhyeṣhu sa yuktaḥ kṛitsna-karma-kṛit
He who can see inaction in action, and action in inaction, is the wisest among men. He is a saint, even though he still acts.
Translated by Shri Purohit Swami
He who sees inaction in action and action in inaction, he is wise among men; he is a yogi and performer of all actions.
Translated by Swami Sivananda
Word meanings (from the gita/gita dataset)
karmaṇi—action; akarma—in inaction; yaḥ—who; paśhyet—see; akarmaṇi—inaction; cha—also; karma—action; yaḥ—who; saḥ—they; buddhi-mān—wise; manuṣhyeṣhu—amongst humans; saḥ—they; yuktaḥ—yogis; kṛitsna-karma-kṛit—performers all kinds of actions