Bukhari

Hadith Commentary:

In another narration, it is stated: “This religion will remain honored until the time of twelve caliphs.”
In the narration of Abu Dawud, it is stated thus: “This religion will remain established until there are twelve caliphs over you, and all will agree upon them.”
These twelve caliphs have already passed in the Ummah of the Prophet (sallallahu alayhi wa sallam).
From Abu Bakr as-Siddiq (radi Allahu anhu) up to Abdul Aziz (rahimahullah), fourteen individuals became rulers.
Among them, the period of rule of two was very brief: one was Muawiyah ibn Yazid, the other was Marwan.
If you exclude them, then there remain exactly twelve caliphs who held the caliphate with great strength and vigor.
After Umar ibn Abdul Aziz (rahimahullah), the nature of the era changed, and although not all people gathered under Hasan and Abdullah ibn Zubair (radi Allahu anhuma), most people did gather under them earlier, so the caliphate of these two gentlemen is also rightful and valid.
The Imamiyyah have taken this hadith as evidence that twelve Imams are intended, i.e., from Ali (radi Allahu anhu) up to Muhammad ibn Hasan al-Mahdi. However, there is a doubt in this, for after Hasan (radi Allahu anhu), people did not gather under any Imam, nor did they attain power and authority; rather, most of them remained in hiding out of fear for their lives. So how can these people be intended by this hadith?
And Allah knows best.

Hadith Commentary:
1.
This narration of Sahih Bukhari is extremely concise because it does not mention the characteristics of the twelve caliphs; it only states that they will be from the tribe of Quraysh.
Other narrations show that during their rule, Islam will flourish greatly and will gain dominance, and its followers will face opposition, but no harm will come to them.
(Sahih Muslim, Al-Imarah, Hadith: 4708(1821) )
In this hadith, two additional points are mentioned which, in terms of chain of narration, are not authentic:
➊.
The Ummah will be united upon these caliphs.
➋.
After them, there will be killing and bloodshed, as Allamah Albani rahimahullah has written about this in detail.
(Silsilat al-Ahadith al-Sahihah, No: 376 )
2.
There is much disagreement regarding the identification of these caliphs, therefore we have deliberately refrained from discussing this. However, the Shia say that by these are meant their alleged twelve Imams, who begin with Ali radi Allahu anhu and end with Muhammad ibn Hasan al-Mahdi, but this is incorrect because during their rule, Islam did not attain any glory or grandeur; rather, most of them remained in hiding to save their lives.
In our view, the Shia position is not based on reality.
And Allah knows best.

Hadith Commentary:
Vocabulary of the Hadith:
(1)
Mani’an:
Powerful and mighty,
protected.
(2)
Sammaneehā an-nāsu:
The people deprived me of it,
meaning, due to the noise of the people I was not able to hear it.