The Hadith
a) Marfu Hadith (Saying of Prophet peace be upon him)
Thawban (May Allah be pleased with him) narrated, "The Prophet(Sal Allah hu alayhe wasallam) said:
: ( يقتيل عند كنزكم ثلاثة كلهم ابن خليفة . ثم لا يصير إلى واحد منهم . ثم نطلع الرايات السود من قبل المشرق . فيقتلونكم قتلا لم يقتله قوم )
ثم ذكر شيئا لا أحفظه . فقال فإذا رأيتموه فبايعوه ولو حبوا على الثلج . فإنه خليفة الله المهدي
"Three men will be killed at the place where your treasure is. Each of them will be the son of a Khalifah, and none of them will get hold of the treasure. Then black banners will come out of the east...' If you see him, go and give him your allegiance, even if you have to crawl over ice, because he is the Khalifah of Allah, the Mahdi."[Ibn Majah no:4084]
b) Moquf Rout (saying of Companion)
Thawban said:
إذا رأيتم الرايات السود خرجت من قبل خراسان فأتوها ولو حبوا ، فإن فيها خليفة الله المهدي "
If you see the black flags coming from Khurasan then go there even if you have to crawl because there is the Khalifah of Allah, the Mahdi."[Mustadrak al Hakim hadeeth no: 8578, Behaqi in Dalail an-Nabuwwah 6/516].
Authentications
a) Imam al-Bazzar said after narrating،
وإسناده إسناد صحيح .
Chain is authentic.
b) Imam Hakim said after narrating:"
هذا حديث صحيح على شرط الشيخين
.This hadeeth is authentic on the criteria of Shaykhayn (Bukhari and Muslim)(end quote)
.
c) Ibn Katheer said
" وهذا إسناد قوي صحيح .This chain is powerful authentic
.
d) Qurtubee authenticated [Tadhkirah 1201]
.
e) Buseri authenticated [Misbah az-Zajjaj 3/263]
.
f) Sindee said
كذا إسناده صحيح رجاله ثقات ورواه الحاكم في المستدرك وقال : صحيح على شرط الشيخين .
Chain is authentic Narrators are trustworthy, narrated by al Hakim in Mustadrak and said Authentic on the criteria of Shaykhayn(Bukhari and Muslim)[Zawaid e Ibne Majah under this hadeeth]
.
g) Hamood at taweejari authenticated [Ittehaaf al Jamah bimaja fi al Fitan wal Malahum wa Sharaait as-Sa`ah 2/187]
.
h) Shaykh Zubair Ali Zai said the marfu rout is weak because of Sufiyan thawri who is mudallis and narrating from (an), but he said regarding the moquf rout
.
The chain of this rout is Hasan Lidhatihi and this is Marfu in hukam.[Al Hadith no: 80 page no: 6]
He also said "Authenticated by Buseri, and al-Hakim authenticated on the criteria of Shaykhayn (Bukhari and Muslim) 4/463,364 and 502. Ad-Dahabee agreed with him, Authenticated by Ibn Katheer[Notes of Ibn Majah hadeeth no: 4084]
These hadith are more authentic than everything else in this issue. There is only one person missing in the chain of transmission and generally you will not find a better chain of transmission. Those people who expect the Mahdi from Medina in KSA find the solution to declare them as weak which is nonesense. Those who declare them as fabricated are rejecting the prophet Mohammad saas.
And Ibn Abi Shaybah, Nu'aym ibn Hammad in al-Fitan, Ibn Majah and Abu Nu'aym narrated from Ibn Mas'ud [radhiyallahu 'anhu] that he said:
"Once we were with the Messenger of Allah [sallallahu 'alayhi wa-sallam], when a group of youths fromBanu Hashim approached. When the Prophet [sallallahu 'alayhi wa-sallam] saw them, his eyes filled with tears and his colour changed.
He [i.e. Ibn Mas'ud] said: "I said: "We see in your face something that worries us." So he said:
"We, the Ahl al-Bayt, are a people for whom Allah has chosen the hereafter over this world. And my household after me will face trials, banishment and pursuit, until a people from the east come with black banners, and they will ask for what is due, but not be given it. So they will fight and be victorious, and be given what they asked for. But they will not accept it from them until they hand it over to a man from my household, who will fill it [i.e. the earth] with equity, as they had filled it with tyranny. So whoever among you reaches that time, then let him go to them, even if he must crawl over ice, for he is the Mahdi."
This hadith came already true with the turks til to the Mahdi part. The turks were living in the east (khorasan)
and settled in anatolia and with the conquest of egypt they have took the trust (Uqab) and will hand over it tho the mahdi.
As for the book the talibans are not this promised army. Hadith about the balck banners do not state they will fight the americans about 11 years. They will be youth and fight only the sufyani in khorasan.