Nasai

1237. Commentary: In this hadith, there is no explicit mention of which type of forgetfulness (sahw) occurred—was it related to the tashahhud or to the two rak‘ahs? In the first case, two prostrations (sajdah) of forgetfulness are to be performed before the salutation (salam), and in the second case, after the salam. There is explicit clarification in other narrations; the ambiguous narration will be interpreted in light of the explicit narrations.

Hadith Commentary:
Vocabulary of the Hadith:

(1)
مَطْهَرَةٌ (mat-harah):
If the letter "meem" carries a kasrah (i.e., is pronounced "mit-harah"), the meaning will be: an instrument for ablution (wudu)—that is, any vessel from which ablution is performed.
And if the "meem" carries a fathah (i.e., is pronounced "mat-harah"), the meaning will be: a place for washing.
Here, taking the meaning as "vessel" is more appropriate.

(2)
عَرَاقِيب (a'raqib):
This is the plural of "عرقوب" (urqub),
the tendon above the heel.

Commentary:
Note:
(The mention of Tashahhud in the hadith is rare.)

1039. Commentary:
In this, there is mention of reciting the tashahhud after the prostrations of forgetfulness (sujud as-sahw) and then concluding with salam. According to this hadith, this is also permissible. However, Shaykh al-Albani rahimahullah has declared this hadith to be shaadh (anomalous).

1018. Commentary:
➊ This hadith is evidence that the incidents of forgetfulness (sahw) were of different kinds.
➋ When a missed rak‘ah or rak‘ahs have to be performed, the opening takbir (takbir al-tahrimah) will also be required for them.

Commentary:
Benefits and Issues:

➊
It is stated in Hadith 1207 that it was the Zuhr (noon) prayer.
This is also supported by a narration from Sahih al-Bukhari. (Sahih al-Bukhari, al-Adhan, Chapter: Should the Imam accept the statement of the people if he is in doubt, Hadith: 715)

➋
It is mentioned in the above narrations
that the Messenger of Allah (sallallahu alayhi wa sallam) performed two rak‘ahs instead of four,
not three.
These narrations are more authentic; however, despite this minor difference, the fundamental issue is established: if, due to forgetfulness, fewer rak‘ahs are performed, then upon realizing, the remainder of the prayer should be completed and the prostration of forgetfulness (sujud as-sahw) should be performed.
There is no need to repeat the entire prayer, even if there is conversation between the imam and the followers.

1238. Commentary: The style of the author (rahimahullah) indicates that he considers the incident in this narration to be the same as the incident in the narration of Abu Hurairah (radi Allahu anhu). However, there are some differences in the details of both. In the earlier narrations, there is mention of the salutation (salam) after two units (rak‘ahs), while in this narration, the salutation is reported after three units (rak‘ahs). According to the first narration, the Prophet (sallallahu alayhi wa sallam) remained in the mosque and did not go home, whereas according to this narration, he went home. Hafiz Ibn Hajar (rahimahullah) inclines to the view that this is one and the same incident, as mentioned previously. However, according to Ibn Khuzaymah (rahimahullah) and others, these are different incidents, because this is what appears from the outward wording of the narrations. And Allah knows best.

1332. Commentary:

➊ Saying the salutation (salam) after the prostration of forgetfulness (sujud as-sahw) is an agreed-upon issue; however, there is a difference of opinion regarding the tashahhud. The narrations about tashahhud are weak. In the general narrations, there is no mention of tashahhud, therefore the preferred and correct position is that there is no tashahhud. The Hanafis consider it obligatory.

➋ For details regarding "kharbaq," see the benefit under hadith: 1230.

Takhrij:
«أخرجه أبوداود، الصلاة، باب ماجاء في التشهد في سجدتي السهو، حديث:1039، والترمذي، الصلاة، حديث:395، والحاكم:1 /323، وأعل بما لا يقدح، وألله اعلم.»©Explanation:
From this hadith, it is understood that when a person praying becomes doubtful about the number of rak‘ahs, he should base his action on the lesser number.
There is a possibility of certainty in this.
This is the position of Imam Malik, Imam Shafi‘i, Imam Ahmad (rahimahumullah), and the majority of scholars. However, Imam Abu Hanifah (rahimahullah) says that in the case of doubt occurring in prayer, one should make taharri, i.e., exert utmost effort to remember; if a predominant assumption (ghalib zann) is formed towards one side, then act upon that, and if after taharri both sides appear equal, then base the action on the lesser number.