ज्ञानं कर्म च कर्ता च त्रिधैव गुणभेदतः। प्रोच्यते गुणसंख्याने यथावच्छृणु तान्यपि ॥

jñānaṁ karma cha kartā cha tridhaiva guṇa-bhedataḥ prochyate guṇa-saṅkhyāne yathāvach chhṛiṇu tāny api

Knowledge, action and actor in the category of qualities are also said to be severally threefold, from the difference of qualities; hear thou duly these also.

In plain words: Krishna says that knowledge, action and the doer each come in three kinds. This depends on the three qualities of nature, called gunas: goodness, passion and darkness. He asks Arjuna to listen as he explains them.