Nasai

133. Commentary: "You did not use to do this before." Hazrat Umar radi Allahu anhu said this considering the general habit or according to his knowledge; otherwise, it is established from you (the Prophet sallallahu alayhi wa sallam) even before the conquest of Makkah on some occasions, for example: on the occasion of Khaybar when sattu (parched barley) was presented to you. See: [صحیح البخاري ، الوضوء ، حدیث : 209]

1:
That is, the mursal narration of Abdur Rahman ibn Mahdi and others, in which there is no mention of the intermediary of Sulaiman ibn Buraidah’s father, is more authentic than the musnad narration of Waki‘, in which the intermediary of Sulaiman ibn Buraidah’s father is mentioned, because its narrators are more numerous.
However, the narration of Abdur Rahman ibn Mahdi through the route of ‘Alqamah is marfu‘ and connected (muttasil) (which is the first chain of the author), and regarding its being connected, there is no disagreement among the students of Sufyan, as there is in the route of Muharib.
“Understand this well (fafham).”

Explanation:
So that no one assumes that multiple prayers cannot be performed with a single ablution (wudu).

Hadith Commentary: Benefits and Issues:
Benefit:
It is established from this hadith that as long as a person does not lose ablution (wudu), he may perform multiple obligatory and voluntary prayers with the same ablution.
This hadith is not contrary to the blessed verse:
﴿إِذَا قُمْتُمْ إِلَى الصَّلَاةِ فَاغْسِلُوا وُجُوهَكُمْ﴾ ()
because the meaning of the blessed verse is:
“If you do not have ablution and you stand for prayer, then perform ablution.”
However, from other narrations it is known that performing ablution while already in a state of ablution is light upon light (nur ‘ala nur), because the Prophet (sallallahu alayhi wa sallam) would generally perform ablution for every prayer,
and the apparent requirement of the verse is just this.
(Sharh al-Nawawi: vol./135)

Benefits:

Wiping over the socks (khuffayn) is permissible. It is permissible to perform multiple obligatory and supererogatory prayers with a single ablution (wudu) as long as a person does not lose his state of ablution. This permissibility is transmitted from the majority of scholars, whereas Abu Ja‘far al-Tabari and Abu’l-Hasan ibn Battal have transmitted from a group of scholars that they consider ablution obligatory for every prayer, even if the person is already in a state of ablution. Their evidence is this verse: «إِذَا قُمْتُمْ إِلَى الصَّلوة فَاغْسِلُوا وُجُوهَكُمْ» [المائدة: 6]. I (Nawawi rahimahullah) believe that this view is not authentically established from any scholar, and it is possible that what is meant is that renewing ablution at the time of every prayer is a recommended (mustahabb) act. There are several authentic hadiths supporting the majority view (that it is permissible to perform multiple prayers with one ablution), among them is the hadith of this chapter, and secondly, the narration in Sahih al-Bukhari from Anas radi Allahu anhu that the Messenger of Allah sallallahu alayhi wa sallam performed the ‘Asr prayer, then consumed sattu (barley drink), and then performed the Maghrib prayer without renewing ablution. Similarly, there are countless narrations with this meaning and purport. In ‘Arafah, Muzdalifah, and all journeys, two prayers are combined with a single ablution, and on the day of the Battle of the Trench, the missed prayers (Zuhr, ‘Asr, Maghrib, and ‘Isha) were performed with one ablution. (All these hadiths are evidence for the permissibility of performing multiple prayers with a single ablution.) And the meaning of the noble verse is that when you are without ablution and wish to establish prayer, then perform ablution. [نووي: 176/3]

Commentary:
* The noble habit of the Prophet sallallahu alayhi wa sallam was that he would perform a new ablution (wudu) for every prayer, but on the day of the Conquest of Makkah, he performed all the prayers with a single ablution.

There can be two reasons for this:

➊ Performing a new ablution for every prayer was obligatory only for him, and not obligatory for the Ummah. Then, this obligation was abrogated on the day of the Conquest of Makkah, and performing a new ablution for every prayer remained only preferable (afdal).

➋ This action of his was recommended (mustahabb), but he abandoned it out of fear that it might be made obligatory upon the Ummah, just as he abandoned performing the Tarawih prayer in congregation. See: (Fath al-Bari: 1/412)