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

Question:
Is the prostration before the closing salam or after it?

Answer:
It is a matter of preference. The preferred practice, if one has closed the prayer due to a deficiency, is to perform it after the closing salam. Likewise, if one proceeded based on a strong presumption, it is after the closing salam. In all other cases, it is before the closing salam. If one prostrates after the closing salam when the preference is to do so before the closing salam, or prostrates before the closing salam when the preference is to do so after the closing salam, that is valid and there is no blame on him. This is because the authentic hadiths indicate this, and the reconciliation between them is this preference. So if one prostrates before the closing salam in the case of a deficiency, it suffices. If one delays the first tashahhud, delays it, and prostrates after the closing salam, there is no blame on him. It is only a matter of preference. The preference is to observe what the Prophet (peace and blessings be upon him) did.
Q: And does he say takbir?
A: He says takbir, yes. He says takbir when prostrating and when rising. This is how it came in the hadith of Abu Hurayrah and the hadith of Imran.