Bhagavad Gita, Chapter 18, Verse 19

Knowledge, action and agent are declared in the Sânkhya philosophy to be of three kinds only, from the distinction of Gunas: hear them also duly.

Krishna signals here that everything just introduced is about to get sorted, real and specific, by the three familiar forces.

This verse acts as a real bridge, tying the new five-factor and triad framework back to the guṇas already explained in earlier chapters. Nothing about this teaching stands apart from what came before.