The Meaning of Anatta - Insight knowledge

Questioner: People gain understanding from listening to the Dhamma. When they practise they can attain the first stage of vipassana nana, “defining of nama and rupa.” They pass that stage.
Sujin: How do they pass that stage?
Questioner: I do not know anything about that.
Sujin: People should not become excited about whether others have passed a stage of insight knowledge. It is by a person’s own understanding that he can know that panna has been developed to the degree of the first vipassana nana. He knows that insight knowledge realizes nama and rupa as they naturally appear, one characteristic at a time, in a mind-door process. At the moments of vipassana nana not merely one kind of nama or one kind of rupa has been penetrated.
Questioner: Someone may have practised insight unto to the fifth stage of maha-vipassana nana, the “knowledge of dispassion” (nibbida nana). He watches the rupa that sits, stands or walks, and he practises until he reaches the “knowledge of dispassion.” I have doubts about how he watches the rupa that sits, stands or walks. How should we practise so that we can attain that stage of vipassana nana?
Sujin: What is the first stage of insight, “defining of nama and rupa”? So long as one has not realized that stage yet one cannot attain “knowledge of dispassion.” There is mindfulness of the body when sati is mindful of one characteristic at a time of rupa paramattha, as it appears through the bodysense. It may be a rupa such as cold, heat, softness, hardness, pressure or motion. Mindfulness of the body is not watching the postures of sitting, lying, standing or walking. When, for example, cold appears, there is only the characteristic of cold, there is no “I,” it is not “mine,” not self. If someone does not know the characteristic of rupa as it appears through one doorway at a time, as only a kind of rupa, he cannot even attain the first stage of insight knowledge, which discerns the difference between the characteristic of nama and the characteristic of rupa. How could panna then realize the stage of “knowledge of dispassion,” the fifth stage of “principal insight” (mahavipassana)?