Bukhari

Chapter of Sahih Bukhari Hadith Number: 7210: «بَابُ بَيْعَةِ الصَّغِيرِ:»
Relevance between the Chapter and the Hadith:
The chapter heading established by Imam Bukhari rahimahullah regarding the pledge (bay‘ah) of a minor boy, in reality, does not indicate its validity, but rather its invalidity.

Allamah Ibn al-Munir rahimahullah states:
«باب بيعة الصغير أى عدم انعقادها شرعًا، لأنه صلى الله عليه وسلم لم يبايعه، فالترجمة موهمة، و الحديث يزيل إيمامها.» [المتوري على ابواب البخاري : ص 235]
“Imam Bukhari rahimahullah established the chapter «باب بيعة الصغير» meaning, legally, it is not valid (the pledge of a minor), because the Prophet sallallahu alayhi wa sallam did not take the pledge from them. Thus, the chapter heading gives an impression, and the hadith removes its ambiguity, so this indicates the invalidity of the pledge of a minor.”

Allamah ‘Ayni rahimahullah, while explaining the relevance between the chapter heading and the hadith, writes:
«ولم يذكر الحكم فيه على عادته غالباً، إما اكتفاءً بما بيّن فى حديث الباب . . . . . فقال جماعة من العلماء البيعة لا تلزم إلا من تلزمه عقود الإسلام كلها من البالغين.» [عمدة القاري للعيني : 396/24]
“Imam Bukhari rahimahullah, according to his usual practice, did not explicitly state any ruling regarding the pledge of a minor child, but sufficed with the chapter heading upon the hadith, which is clarified thereby . . . . . The scholars have said that the pledge is obligatory upon those for whom the contracts of Islam are obligatory, who are among the adults.”

That is, in summary, Imam Bukhari rahimahullah did not clarify in the chapter whether the pledge should be taken from a minor or not; rather, the hadith presented under the chapter itself will be the meaning of the chapter.

Hadith Commentary:
This is the Sunnah: that on Eid al-Adha, one goat should be sacrificed on behalf of each household.
A single goat on behalf of all the members of the household is sufficient.
Now, the custom that has become prevalent, where many goats are sacrificed, is contrary to the Sunnah of the Prophet (sallallahu alayhi wa sallam), and people have adopted this practice merely out of pride, as has been mentioned in Kitab al-Udhiyyah.
Hafiz Abdullah ibn Hisham (radi Allahu anhu), due to the blessing of the supplication of the Prophet (sallallahu alayhi wa sallam), lived for a very long time.

Hadith Commentary:
From this hadith, it is understood that it is not obligatory for children to pledge allegiance (bay‘ah), as the Messenger of Allah (sallallahu alayhi wa sallam) said regarding Abdullah bin Hisham (radi Allahu anhu) that he was still young. However, the Prophet (sallallahu alayhi wa sallam) made supplication (du‘a) for him, and by the blessing of this supplication, he lived for a long time after the Messenger of Allah (sallallahu alayhi wa sallam) in good health and safety.
(Fath al-Bari: 13/248)
However, children may pledge allegiance (bay‘ah) along with their fathers, as Abdullah bin Zubair (radi Allahu anhu) pledged allegiance to the Messenger of Allah (sallallahu alayhi wa sallam) at the age of eight, together with his noble father.
(‘Umdat al-Qari: 16/457)

Benefits and Issues:
Allegiance (bay‘ah) is not a mere formal or ceremonial act.
Rather, it is a contract between both parties.
Therefore, a person should pledge allegiance thoughtfully and with understanding.
Whether the allegiance is for jihad, for migration (hijrah), or for adherence to righteous deeds (a‘maal saalihah), however, the third type of allegiance (allegiance for adherence to righteous deeds) was not customary in the era of the Salaf (the Companions and the Followers).
This practice was established after the best generations (khayr al-quroon).