Chapter: The Two Prostrations of Forgetfulness (Sujud al-Sahw) for Decrease [and] Increase.

• I heard Ahmad ibn Hanbal say—regarding the two prostrations of forgetfulness when they are from an act of deliberation (taharri), or if one performs the taslim after two or three rak'ahs—that it is: "After the taslim, and all other (cases) are before the taslim."

• I heard Ahmad—another time—say: "Forgetfulness occurs in five ways:

1 - Forgetfulness during deliberation (taharri): based on the hadith of Ibn Mas'ud; he prostrates after the taslim and the tashahhud.

2 - In the hadith of Zayd ibn Aslam, from 'Ata' ibn Yasar, from Abu Sa'id; he prostrates them before the taslim and does not recite the tashahhud.

3 - In the hadith of Ibn Buhaynah; he prostrates them before the taslim and does not recite the tashahhud.

4 - In the hadith of Abu Hurayrah and 'Imran ibn Husayn—regarding performing the taslim from two or three (rak'ahs)—he prostrates after the taslim and recites the tashahhud in them.

5 - And he said: "Every forgetfulness that enters upon him other than these, he performs it before the taslim, because it is more correct in meaning, as if he omitted a prostration, a rak'ah, or the Fatihat al-Kitab (Opening Chapter of the Book)."

• Ahmad was asked—another time—about the hadith of Ibn Mas'ud that the Prophet (peace be upon him) prayed Dhuhr as five (rak'ahs); I asked: "Did he sit in the fourth?" He said: "It is not in the hadith." He said: "And this is Zayd ibn Aslam saying: 'If he doubts between the fourth and the fifth, he considers it four'," meaning: the hadith of Zayd ibn Aslam, from 'Ata' ibn Yasar, from Ibn 'Abbas."