If one forgets that he is in a state of ritual impurity while praying, does he complete the prayer or not, and is there scholarly disagreement on this issue?

Al-Halabi : My teacher, regarding something else on the same topic.

The Shaykh: Yes.
Al-Halabi : I mean, may Allah know best, that there is a difference between one who enters a state of ritual impurity and one who remembers that he is in a state of ritual impurity.

The Shaykh : Yes, exactly.
Al-Halabi : So this does not prevent, may Allah know, that he builds upon what has passed!

The Shaykh : It is itself a matter of scholarly disagreement among the jurists now.
Al-Halabi : This same one?

The Shaykh : No, no, the one who entered a state of ritual impurity, the one who entered a state of ritual impurity.
Al-Halabi : There is disagreement in it.

The Shaykh : Yes, the disagreement in it has ended, there is disagreement in it, but this last scenario—also—does he restart or build upon what has passed? There are two opinions in this issue as well, and this one who entered a state of ritual impurity can be attached to this story, the story of Abu Bakrah al-Thaqafi. Yes, that is right.