Verse 20

20.  Atman is imagined as Prana,  by the Prana knowers,    and as qualities   (elements),  Knowers of them   (the qualities);   as Gunas,  the Guna knowers;   and as Tattvas,  the Knowers of them the Tattvas.

"Atman is imagined as Prana,  by the Prana knowers"

Atman,  the nature of being truth and reality,  is also attributed to Prana,  or vital force by those described as  "knowers".  Knowers are those whose knowledge relies totally on memorised worldly experiences.  As described previously,  our experiences take place within the Maya and delusion of conscious   "states",  waking or dreaming and so forth.  Because these  "states"  of consciousness are themselves a delusion of Maya,  therefore all knowledge gained through experience within these states is based on delusion.

"as qualities   (elements),  Knowers of them   (the qualities)"

The  "knowers"  whose knowing comes from sensory knowledge also see the duality of elements with qualities as their reality.

"as Gunas,  the Guna knowers"

The  "knowers"  who see the forms and changes of energy as having true being are also those deluded by this apparent duality.

"and as Tattvas,  the Knowers of them the Tattvas"

The  "knowers"  of Tattvas or separate causes of the universe are also those whose dependence on sensory knowledge leads them to the delusion of duality.