When is the prostration for forgetfulness performed after the closing salam? And when is it performed before it?

Question:
The Shaykh said: When is the prostration for forgetfulness performed after the closing salam? And when is it performed before it?

Answer:
The prostration before the closing salam is the preferred practice, except in two cases:
The first is: if one builds his prayer on his predominant assumption, the preferred practice is to perform it after the closing salam.
The second case is: if one says the closing salam while missing one or two units of prayer, and then realizes it, he completes the prayer, then says the closing salam, then performs the prostration for forgetfulness. This is the preferred practice in these two cases. The first is: if one builds his prayer on his predominant assumption, he investigates the truth, builds on his predominant assumption, then completes his prayer, then says the closing salam, then performs the prostration for forgetfulness. The second case is if he says the closing salam while missing two or three units, and then realizes it, or is reminded, he completes his prayer, and when he completes it and says the closing salam, he performs the prostration for forgetfulness. This is the preferred practice. In all other cases, it is performed before the closing salam.

The presenter: May Allah reward you and bless you.