ज्ञानं कर्म च कर्ता च त्रिधैव गुणभेदत: |

प्रोच्यते गुणसङ् ख्याने यथावच्छृणु तान्यपि ||

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



गुणों की संख्या करने वाले शास्त्र में ज्ञान और कर्म तथा कर्त्ता गुणों के भेद से तीन-तीन प्रकार के ही कहे गये हैं, उनको भी तू मुझसे भली-भाँति सुन ॥19॥


Knowledge, action, and the doer are declared to be of three kinds in the Sānkhya philosophy, distinguished according to the three modes of material nature. Listen, and I will explain their distinctions to you.


English Translation Of Sri Shankaracharya’s Sanskrit Commentary By Swami Gambirananda

18.19 Jnanam, knowledge; karma, action-not the objective case in the technical sense, which is defined as ‘that which is most cheirshed by the subject’; and karta, agent, the accomplisher of actions; procyate, are stated; guna-sankhyane, in the teaching about the gunas, in the philosophy of Kapila; to be eva, only (-only is used for emphasis, by way of showing that they have no classification other than that based on the gunas-); tridha, of three kinds; guna-bhedatah, according to the differences of the gunas, i.e. according to the differences of sattva etc.
Even that philosophy teaching about the gunas is certainly vaild so far as it concerns the experiencer of the gunas, though it is contradictory so far as the non-duality of the supreme Reality, Brahman, is concerned. Those followers of Kapila are acknoweldge authorities in the ascertainment of the functions of the gunas and their derivatives. Hence, that scripture, too, is being referred to by way of eulogy of the subject-matter going to be spoken of. Therefore there is no contradiction.

Srnu, hear; tani, about them; api, also; yathavat, as they are, as established by reason and as propounded in the scriptures. Hear about knowledge etc. and all their diversities created by the differences of the gunas. The idea is , ‘Concentrate your mind on the subject going to be taught.’
And now the threefold classification of knowledge is being stated: