Chapter 18 · Liberation through Renunciation · Krishna said
Bhagavad Gita 18.19 — Threefold by gunas
ज्ञानं कर्म च कर्ताच त्रिधैव गुणभेदतः। प्रोच्यते गुणसङ्ख्याने यथावच्छृणु तान्यपि ॥
jñānaṃ karma ca kartāca tridhaiva guṇabhedataḥ | procyate guṇasaṅkhyāne yathāvacchṛṇu tānyapi ||
Meaning
Sankhya teaches that knowledge, action and the doer are each of three kinds according to the gunas. Listen to them properly.