Different Kinds of Purity - 5th Purity - 1

The fifth purity is Purity by knowledge and vision of what is the path and what is not the path (maggamagga-nana-dassana-visuddhi).
When purity by overcoming doubt has arisen, panna becomes more accomplished through satipatthana, which is aware of the characteristics of nama and rupa. Panna becomes more familiar with their characteristics and comes to know them more clearly. Panna realises that realities are equal in the sense that all of them are only conditioned dhammas, and thus there is more equanimity with regard to them. This means that there is more detachment, less inclination to cling to any particular nama or rupa. Panna is more inclined to investigate the arising and falling away of the nama and rupa which appear, their characteristics of impermanence, dukkha and anatta. Thus, panna can realise the arising and falling away of dhammas in succession, at the stage of insight which is comprehension by groups, (sammasana nana). After that stage there can be the fourth stage of insight that is knowledge of the arising and falling away of realities (udayabbaya nana). This is a more precise knowledge of the arising and falling away of one kind of nama and one kind of rupa at a time.
A person who is a beginner in insight can have “imperfections of insight.” After the fourth stage of insight has fallen away, defilements can arise. Since they have not been eradicated they can condition the arising of one or more “imperfections of insight” (vipassanupakkilesas; see Visuddhimagga Ch XX, 105-129). There are ten imperfections of insight, arising on account of the following factors:
Illumination  (obhasa), Insight knowledge  (vipassana nana), Rapture  (píti), Tranquility  (passaddhi), Happiness  (sukha), Resolution  (adhimokkha), Exertion  (paggaha), Assurance  (upatthana), Equanimity  (upekkha), Delight  (nikanti).