Bhagavad Gita Chapter 18, Verse 19

ज्ञानं कर्म च कर्ता च त्रिधैव गुणभेदतः | प्रोक्तमगुणतो नैव त्रिविधं शृणु तान्यपि ||

jñānaṁ karma ca kartā ca tridhaiva guṇa-bhedataḥ proktam aguṇato naiva trividhaṁ śṛṇu tāny api

Knowledge, action, and the doer are indeed of three kinds according to the gunas. Hear Me also explain those three kinds, which were declared without reference to the gunas.

Krishna emphasizes the comprehensive classification. This verse restates the teaching that knowledge, action, and the doer are of three kinds according to gunas (jñānaṁ karma ca kartā ca tridhaiva guṇa-bhedataḥ). The emphasis on 'tridhaiva' (indeed three kinds) and 'guṇa-bhedataḥ' (according to gunas) shows that this classification is fundamental. Everything is classified by the gunas. The teaching that follows will detail the three kinds of knowledge, then the three kinds of action, then the three kinds of doer. Understanding this comprehensive classification helps you see yourself clearly: your knowledge, your actions, and your sense of doing all reflect the gunas. This is the path to self-awareness and alignment with sattvic qualities.