Bukhari

Hadith Commentary:
Ibn Abbas (radi Allahu anhu) did not pass in front of the Messenger of Allah (sallallahu alayhi wa sallam) during the congregational prayer, but rather passed in front of some of the followers (muqtadis).
Since the barrier (sutrah) of the imam is considered the barrier for the people (praying) behind him, the Messenger of Allah (sallallahu alayhi wa sallam) did not reprimand him.
When the congregation is being held, it is strictly prohibited to pass in front of the imam, and when a person is praying individually, it is strictly prohibited to pass in front of him.
Both the imam and those praying individually should ensure that they place a barrier (sutrah) in front of them.
Since this hadith mentions the Farewell Pilgrimage (Hajjat al-Wada‘), Imam Bukhari (rahimahullah) has included this hadith here.

Hadith Commentary:
From this hadith as well, Imam Bukhari rahimahullah has established the purpose of the chapter.
Ibn Abbas radi Allahu anhu was not yet of age (i.e., had not reached puberty) at that time; his participation in the row (saff), performing ablution (wudu), and offering prayer is thus established.
It is also understood from this that even before reaching puberty, boys must certainly be habituated to prayer.
For this reason, it is necessary to instruct them to pray from the age of seven, and upon reaching the age of ten, they should be made accustomed to prayer even by stern admonition.

Hadith Commentary:
From this hadith, it is understood that when a child becomes intelligent and alert, he can bear (memorize and retain) hadith, but for the narration (transmission) of hadith, it is a condition that he be mature (baligh).

Imam Yahya ibn Ma'in states that for bearing hadith, the minimum age of the narrator should be fifteen years, because the Messenger of Allah (sallallahu alayhi wa sallam) did not allow Ibn Umar (radi Allahu anhuma) to participate in the battle on the day of Uhud, and similarly, Bara’ ibn Azib (radi Allahu anhu) was also sent back on the occasion of the Battle of Badr, because both of them were under fifteen years of age. However, Imam Ahmad ibn Hanbal (rahimahullah) says that for bearing hadith, being intelligent and alert is necessary, but there is no restriction regarding age.

The reason why the Messenger of Allah (sallallahu alayhi wa sallam) did not allow certain companions to participate in battle was that strength and understanding of matters are required in war. Therefore, he sent back those of younger age. However, for bearing hadith, physical strength is not required; rather, it depends solely on alertness and intelligence.

If an intelligent child narrates something from his childhood after reaching maturity, it will be considered reliable. Accordingly, from this hadith of Ibn Abbas (radi Allahu anhuma), the hadith scholars have derived several rulings.

(Fath al-Bari: 1/225)

Hadith Commentary:
Abdullah ibn Abbas (radi Allahu anhu) was at that time not yet of age (a minor).
Despite this, he performed Hajj with the Messenger of Allah (sallallahu alayhi wa sallam). Imam Bukhari (rahimahullah) has established the purpose of the chapter from this very point.

753. Commentary: Imam Bukhari rahimahullah is of the opinion that there was a sutrah (barrier) in front of the Messenger of Allah sallallahu alayhi wa sallam, as is evident from other detailed narrations. Therefore, the imam’s sutrah is sufficient for the followers (muqtadis). See: [صحیح البخاري ، الصلاة ، حدیث : 493]
For this reason, this narration should not have been included under this chapter. Some people have deduced from this narration that the passing of a donkey does not invalidate the prayer, but this deduction is weak because the discussion of invalidation or non-invalidation arises only when there is no sutrah in front and the animal passes between the sutrah and the worshippers.

Benefit:
It is understood from this that if a donkey passes in front of someone performing prayer, the prayer is not invalidated, whereas in Hadiths 950 to 952 it is mentioned that the prayer is invalidated by the passing of a donkey. However, deducing from this hadith that the prayer is not invalidated is not a strong argument, because the barrier (sutrah) of the imam suffices for the followers, and Ibn Abbas radi Allahu anhu did not pass in front of his imam, the Prophet sallallahu alayhi wa sallam.

Benefit:
From this hadith, it is understood that the donkey is not impure; only its meat is forbidden to eat. Riding on it is permissible. The sutrah (barrier placed in front during prayer) of the imam is considered the sutrah for all followers; they do not need to place a separate sutrah. This hadith also establishes the authority (hujjiyyah) of a tacitly approved (taqreeri) hadith.