Bukhari

Hadith Commentary:
(So there will be no Caesar after him)
In al-Sham, he (sallallahu alayhi wa sallam) said this to comfort the hearts of his companions from Quraysh and to give them glad tidings that the rule of both (Caesar and Chosroes) would be removed from the aforementioned regions. This is because they used to travel to al-Sham and Iraq as merchants, and when they embraced Islam, they feared that their journeys to those lands would be cut off due to their entering Islam. So he (sallallahu alayhi wa sallam) said this to them. This was stated by our great Imam al-Shafi'i. Caesar lived until the time of Umar, in the year twenty (after Hijrah), according to the correct view, and his rule remained; it was only removed from al-Sham (al-Qastallani).

That is, after his destruction, there will never again be a Caesar in al-Sham.
The Prophet (sallallahu alayhi wa sallam) said this as glad tidings to his noble companions that soon the kingdoms of Chosroes and Caesar would come to an end.
These Qurayshi companions, before Islam, used to travel to these countries for trade. After embracing Islam, they feared for their ability to continue these journeys, so the Prophet (sallallahu alayhi wa sallam) gave them this glad tiding.
Chosroes tore up the blessed letter of the Prophet (sallallahu alayhi wa sallam), so by the Prophet’s (sallallahu alayhi wa sallam) supplication against him, his kingdom was torn apart and his name and trace were erased from the face of the earth.
Caesar, on the other hand, honored and respected the blessed letter of the Prophet (sallallahu alayhi wa sallam), so the Prophet (sallallahu alayhi wa sallam) supplicated for the continuation of his kingdom.
Thus, his rule was cut off from al-Sham but remained in Rome. Regarding the land of al-Sham, the prophecy of the Prophet (sallallahu alayhi wa sallam) concerning both kingdoms was fulfilled to the letter (sallallahu alayhi wa sallam).

Hadith Commentary:
This prophecy of the Noble Messenger (sallallahu alayhi wa sallam) was fulfilled word for word: after the rise of Islam, the ancient Persian empire came to a permanent end, and for fourteen hundred years, Iran has remained under the dominion of Islam.
The same happened with Syria.
Their treasuries, which had been accumulated over thousands of years,
came into the hands of the Muslims and were distributed among those entitled to them.
The Messenger of Allah (sallallahu alayhi wa sallam) spoke the truth.

Hadith Commentary:
In both these hadiths, there is mention of a prophecy of the Messenger of Allah (sallallahu alayhi wa sallam) which was fulfilled word for word.
That is, after the rise of Islam, the ancient Persian empire and the Roman government would come to an end, and so it happened: the fire temple of Iran was extinguished forever, and the Roman government was also annihilated.
The treasures of both these governments came into the hands of the Muslims and were distributed among those entitled to them.
Allah, the Exalted, purely out of His grace, made the treasures of these governments lawful for the mujahideen, which came into their hands in the form of spoils (ghanimah).