Tirmidhi

1:
The narrators of this hadith are not people of Madinah, rather they are people of the East (the people of Kufa and Basra). The meaning is that these individuals are not as reliable as the people of Madinah.

Note:
(In the chain of narration, Abdur Rahman al-Ifriqi is weak, and Abu Ghutayf is unknown.)

Explanation:
In this, the action of the Prophet sallallahu alayhi wa sallam is described, that he used to perform fresh ablution (wudu) for every prayer. So this was his predominant practice; otherwise, on some occasions, he also performed multiple prayers with a single ablution, as is evident from the next narration as well.

Commentary:
(1)
The ablution (wudu) performed for one prayer remains valid for performing other obligatory (fard) and voluntary (nafl) prayers as long as the original ablution persists.

(2)
It is permissible to perform a new ablution for another prayer even if the first ablution has not been nullified, and this practice—performing ablution upon ablution—is considered superior. However, if the first ablution is nullified, then it is necessary to perform a new ablution for the next prayer. ( : Sahih al-Bukhari, Book of Ablution, Chapter: Prayer is not accepted without purification, Hadith: 135; Sahih Muslim, Book of Purification, Chapter: The obligation of purification for prayer, Hadith: 224)