Bhagavad Gītā Chapter Four verse 17

karmaṇo hyapi boddhavyaṃ boddhavyaṃ ca vikarmaṇaḥ |
akarmaṇaśca boddhavyaṃ gahanā karmaṇo gatiḥ ||

karman - act, action, performance; work, labour, activity; any religious act or rite; organ of sense

Commentaries and Reflections

Commentary by TKV Desikachar:

Karma is the means to know oneself.