"In this sutra, they make it very clear that a person has to come to a level where only pure knowledge flows from his system. Nothing else. Nothing can make that knowledge vitiated or tinted. Knowledge has to be pure and clear. And the knowledge they are talking about is the clarity in what is Purusha and Prakriti.
Purusha is pure consciousness, permanent, which can't be destroyed. It's there, it's going to be there. Sattvik state is very close to Purusha. And Prakriti is ever changing with all colours, flavours, varieties, all creations. Both of these things are totally separate.