The Stages of Vipassana - 13th stage of vipassana nana

The thirteenth stage of vipassana nana is Change-of-lineage knowledge (gotrabhu nana).
This knowledge succeeds the anuloma nana, which includes three moments of citta for the person who realises the Noble Truths more slowly than a person with keen panna, and two moments for a person with keen panna. Change-of-lineage knowledge is maha-kusala citta nana-sampayutta and this citta has nibbana as object. It is repetition-condition (asevana- paccaya)  for the succeeding magga-citta of the stage of the sotapanna, which is lokuttara kusala citta. The magga-citta has nibbana as object and eradicates defilements.
In the process of cittas all seven javana-cittas usually have the same object, but it is different in the case of the magga-víthi. The cittas that are parikamma (preparatory consciousness) upacara (access) and anuloma (adaptation) have as object one of the three general characteristics of conditioned realities. The following cittas in that process, the gotrabhu (change-of-lineage) the magga-citta and the moments of phala-citta (two or three moments), have nibbana as object. Gotrabhu is maha-kusala citta that has for the first time nibbana as object. It is, as it were, “adverting” to the magga-citta of the stage of the sotapanna that succeeds the gotrabhu and has nibbana as object. The Visuddhimagga (XXII, 11) states that this citta, since it can only realise nibbana but not dispel defilements, is called “adverting to the Path.” We read:

For although it is not adverting (avajjana),

it occupies the position of adverting;

and then, after as it were giving a sign to the path to come into being,

it ceases.
The path-consciousness that succeeds it can then, while it experiences nibbana, eradicate defilements. The Atthasaliní (II, Book I, Part VII, Ch I, the first Path, 232, 233) and the Visuddhimagga (XXII, 8-10)) use a simile for anuloma nana and gotrabhu nana. A man went out at night in order to look at the moon. The moon did not appear because it was concealed by clouds. Then a wind blew away the thick clouds, another wind blew away the medium clouds and another wind blew away the fine clouds. Then that man could see the moon free of clouds. Nibbana is like the moon. The three moments of anuloma nana (adaptation knowledge) are like the three winds. Gotrabhu nana is like the man who sees the clear moon in the sky, free of clouds. As the three winds are able only to disperse the clouds covering the moon and do not see the moon, even so the three moments of anuloma nana are able only to dispel the murk that conceals the Noble Truths but they cannot experience nibbana. Just as the man can only see the moon but cannot blow away the clouds, so gotrabhu nana can only experience nibbana but cannot dispel defilements.