What does the hadith about a caliphate on the pattern of prophethood mean?
A caliphate on the pattern of prophethood always follows a prophet and cannot grow out of a monarchy. The second caliphate the hadith speaks of therefore presupposes the coming of the promised Messiah.
The hadith in question describes a sequence. First comes prophethood. It is followed by a caliphate on the pattern of prophethood. After that come times of harsh rule and tyranny. And finally, a caliphate on the pattern of prophethood arises once again.
The decisive question is what such a caliphate comes from. A caliphate on the pattern of prophethood is not a political office that a ruler can seize. It continues the work of a prophet. That is why the first caliphate arose directly after the Holy Prophet Muhammad (saw). The hadith above shows that he himself spoke of successors to whom the believers should remain loyal.
Such a caliphate cannot grow out of a monarchy or a despotism. So when the hadith announces a second caliphate after the times of tyranny, a prophet must once again precede it. This points to the Messiah whose coming is promised for the latter days. Only after him can a caliphate on the pattern of prophethood arise again.
One more thing stands out. The hadith says nothing about an end to this second caliphate. Of the first, it announces that another age will follow it. Of the second, it is silent. This suggests that it will endure for a long time.
The verse above makes clear that this caliphate is a gift from God to the believers. It serves to strengthen their faith and to turn their fear into security.