ibn-hajar in his 'sawaeq' narrates from abu na'eem who narrates from ibn-abbass that the holy prophet (s.a.w.a.) said:- 'a nation whose first is myself; whose last is isa-ibn-maryam and centre one Mahdi will never be destroyed'.
the same tradition can be found on page 151 of «esaaf-ur-rhagebeen».(69)
the author of «eqdud-durar» ,has narrated (in the seventh chapter) from 'sunan' of nesa'ee and he from anas-ibn-malik that 'the holy prophet (s.a.w.a.) said:- 'destruction is not for a nation in which i am the first of it, Mahdi the middlemost and messia h the last'.
ganji in his book of 'bayan', after narrating the afore-said tradition says: 'this tradition is 'hassan' (good) and hafez abu na'eem and ahmad-ibn-hanbal have narrated it in their books 'awali' and 'musnad' respectively. his saying that 'isa shall be the last' does not mean that isa will remain alive after Mahdi because, as it has been proved that Mahdi is the last imam and except for him, no other imam has been mentioned by them, it is not possible for the people to remain without an imam. if it is said that isa shall lead the people after him for some time we reply:-
in case isa remains amongst the people, it cannot be said that there will not remain any goodness and joy even though traditions mention that after Mahdi, there shall be no goodness and joy. it is not authorized that isa acts and leads as a vicegerent because his dignity is much higher than the position of vicegerency. moreover, he cannot enjoy liberty in his leadership as the ignorant people shall start imagining muhammad's nation to have changed and converted into a christian nation and this imagination is blasphemy. therefore, it is necessary to interpret the tradition in this manner that muhammad (s.a.w.a.) was the first leader and the first inviter of islamic 'shariat' and Mahdi was the middle inviter. this interpretation appears to be correct to me. it is also possible to interpret Mahdi's middle stage as his superiority and betterment over the others because he is the imam and isa shall descend after him and confirm his position of imamate. moreover he shall become his associate and helper in his affairs and declare to the people the integrity of whatever imam claims. therefore isa is his last confirmer.
the author of «kashful-ghumma» after mentioning what we have narrated from the book of 'bayan' regarding the interpretation of this tradition says:-
if, by middleness of Mahdi is meant his superiority then it is apprehended that he will be better than ali too and i can find no person believing in this talk. however, we may interpret this as such: the holy prophet (s.a.w.a.) was the first inviter and he placed Mahdi in the middle since he was amongst his followers and 'ahl-e-bit'. he was nearer than his other followers and better placed in the centre than those living on his path. however, since isa was already the leader of one nation and would invite (the people) in the end towards another nation (i.e. islam) he deserves to be called the last inviter towards islam and Allah is all-knowing.'
author says: the details regarding these two noble traditions which we have mentioned is that we say: the word of negation (--) denotes nullity forever. that is to say, if this letter appears in a word it shall render it ineffective (shall not occur). 'destruction' in tradition either refers to worldly torments (just as some of the previous nations got afflicted by it) or deviation after receiving guidance and blasphemy after having belief (just as it occurred with some of the previous nations). or it refers to disconnection of the field of social life. just as a person dies, a nation too dies and fades away. as Allah says ---
(--) or (--) (middle) has to be interpreted in its very apparent meaning which is something between the first and last. it does not refer to superiority or betterment because in the second tradition the word of 'middle' has been used as against the words of, 'first' and 'last' and secondly the word of (--) (in the first tradition) is a part of the word (--) and earned the meaning of 'valency'. thus one cannot interpret (--) to mean betterment. the holy prophet (s.a.w.a.) being the 'first' is an apparent enough evident. however Mahdi, being the 'middle' emerges from this view-point that he has been born in the year 256 and from then onwards he is living until Allah makes him to reappear. isa being the 'last' one indicates this fact that he shall descend after the emergence of Mahdi. the words 'first', 'last' and middle have been used in the literal sense for these three personalities and not in any other sense.
after becoming aware of what we have written we say: although Allah is all-knowing, (yet) what the holy prophet (s.a.w.a,) meant by this saying is that destruction and annihilation never overtakes a nation which has been associated and related to such kind of sacred systems. therefore, it is by the blessing of these three personalities that Allah has refrained from sending worldly chastisement or that deviation will not occur for them as a result of the teachings and training of these three personalities (either directly or indirectly) or that by being attentive to people like them and their reformatory instructions, a nation shall not be destroyed and will not lose its social life.