Tirmidhi

English Commentary:
1:
Staying and encamping at Muhassab is not among the rites of Hajj.
The Messenger of Allah (sallallahu alayhi wa sallam) stayed here after the decline of the sun (zawal) in order to rest.
He performed the Zuhr and Asr, as well as Maghrib and Isha prayers, and spent the night of the fourteenth there.
Since he encamped here, staying at this place is considered recommended (mustahabb) in following him.
The Caliphs (khulafa) acted upon this after him.
Imam Malik, Imam Shafi'i, and the majority of the scholars have, in imitation of the Messenger of Allah (sallallahu alayhi wa sallam) and the Rightly Guided Caliphs (radi Allahu anhum), declared it recommended. If someone does not encamp there, then by consensus, there is no harm in it.

Hadith Commentary:

Staying at Muhassab is not a pillar (rukn) of Hajj. The Prophet (sallallahu alayhi wa sallam) stayed there for rest, with the thought that departure towards Madinah would be easier from that place. Accordingly, he performed both the Asr and Maghrib prayers there. Even though he (sallallahu alayhi wa sallam) stayed there only for this reason, this stay became recommended (mustahabb), and after him, Abu Bakr (radi Allahu anhu) and Umar (radi Allahu anhu) also used to stay there.

Hadith Commentary:
(1)
Is staying in the Valley of Muhassab (Wadi Muhassab) a Sunnah or not? There is a difference of opinion among the early scholars (salaf) regarding this.
Aishah (radi Allahu anha) and Ibn Abbas (radi Allahu anhuma) did not consider camping there to be a Sunnah, because the Messenger of Allah (sallallahu alayhi wa sallam) only stopped there after midday for the purpose of resting.
He performed the two Asr prayers and the two Maghrib prayers there.
Camping at this place is not among the rites (manasik) of Hajj.
Ibn Umar (radi Allahu anhu) considered camping there to be a Sunnah, because the descent of the Messenger of Allah (sallallahu alayhi wa sallam) at that place is established, and the Rightly Guided Caliphs (khulafa’ rashidun) also acted upon this. However, according to him as well, it has no connection to Hajj; rather, it can be considered a separate Sunnah.

(2)
According to us, the Messenger of Allah’s (sallallahu alayhi wa sallam) camping in the Valley of Muhassab was to express gratitude to Allah, because Allah granted dominance to Islam, while the polytheists had sworn oaths at that place to annihilate Islam. On this basis, stopping there can be considered recommended (mustahabb) if one passes by, but camping there has no connection to the rites (manasik) of Hajj.
And Allah knows best.

Benefit:
It is in the Valley of Muhassab, but it is not related to the sites of Hajj.