The one with the misconception and confusion would say that Hussain a.s. comes after Imam AlMahdi pbuh and not Ahmed and since this is the case the Question will be as follows:”Is there a hadeeth which says that after the Mahdi MUHAMMAD SON OF ALHASAN A.S. (emphasizing the name) Hussain a.s. will rise and bury him when he dies? There isn’t a single hadeeth mentioning that Hussain a.s. will bury the one with name of the Imam that we mentioned except Mahdi or Riser in the hadeeths and Imam Ritha a.s. explained this so well when he was asked this question before.
Ali son of Abi Hamza AlBata’eni said to Imam Ritha pbuh “We narrated that the Imam will not pass away until he sees his offspring.He said Abu AlHassan(AlRitha pbuh): Did you narrate a different hadeeth than this? He said: No. He said: Yes by Allah you have narrated, except the Riser and you do not know what it means and to whom it was referring to. So Ali Ibn Hamza said:Yes by Allah, this is in the hadeeth. Abu AlHasan a.s. said: Woe onto you, how can you be so sure about something when you left some of it.And then he said: O Sheikh fear Allah and do not be from among those avoiding the religion of Allah.
v.2 p.73 Mirza AlNoori Najm AlThaqib
وروى بسنده عن اسماعيل بن سهل عن بعض أصحابنا حديثاً طويلاً عرض فيه النقاش الدائر بين البطائني والامام الرضا (ع) حول إمامته. وجاء في آخره: أن البطائني قال: «إنا روينا أن الامام لا يمضي حتى يرى عقبه. فقال أبو الحسن (ع): أما رويتم في هذا الحديث غير هذا. قال: لا. قال (ع): بلى واللّه لقد رويتم إلا القائم، وأنتم لا تدرون ما معناه، ولمَ قيل. قال له علي: بلى واللّه إن هذا لفي الحديث. قال له ابو الحسن (ع): ويلك كيف اجترأت على شيء تدع بعضه. ثم قال: يا شيخ إتق اللّه، ولا تكن من الصادين عن دين اللّه تعالى»
http://www.alseraj.net/maktaba/kotob/re … s/a31.html
So pay attention to this part”And you do not know what it means to whom it was referring to” if it was talking about Imam Al Mahdi a.s. it wouldn’t have been hidden from a man like Ali son of Abi Hamza AlBata’eni who excelled in memorizing the narrations of Ahlulbayt a.s. And how can it be hidden from him and most of the people around that time knew that the Riser that is being discussed is the Imam Al Mahdi a.s. So since the meaning is “no offspring for him” was hidden from Ali son of Abi Hamza AlBata’ini and the rest from the narrators, it must be meant to someone different than Imam Al Mahdi pbuh and he is the last of the Mahdis from the offspring of Imam Al Mahdi a.s. which is the meaning that was intended from Imam Al Ritha a.s. when he said “and you do not know to whom it was referred to and what it was meant” Bihar Al Anwar v.48 p.270
Its clear from many hadeeths(who wants to review this can read the 100 hadeeths thread and the supplications) that Imam AlMahdi a.s. has an offspring, so this Mahdi is not Imam AlMahdi a.s. Muhammad son of AlHasan. The one whom during his time-that the Raja[Return] will take place and Imam Hussain a.s. will burry him- is the last Mahdi the 12th Mahdi pbuh who has no offspring.
عن الحسن بن علي الخزاز قال دخل علي بن أبي حمزة على أبي الحسن الرضا عليه السلام فقال له أنت إمام قال نعم قال فإني سمعت جدك جعفر بن محمد يقول لا يكون الإمام إلا و له عقب فقال له أ نسيت يا شيخ أم تناسيت ليس هكذا قال جعفر إنما قال لا يكون الإمام إلا و له ولد إلا الإمام الذي يخرج عليه الحسين بن علي فإنه لا عقب له قال صدقت جعلني الله فداك هكذا سمعت جدك يقول
Mirza AlNoori in Najm AlThaaqib v.2 p.73 After when he mentioned 12 evidences about the offspring of Imam AlMahdi a.s. he said(….and there isn’t a report that conflicts with these reports except the hadeeth that the Thiqa Sheikh who is grand AlFathel Ibn Shaathan AlNaysaboori in his Gaiba with a Sanad that is Saheeh from AlHasan son of Hazaz..he said: I entered to Ali ibn Abi Hamza who was with Abi alHasan alRidha (as), he told him (as): Are you an Imam? He (as) said: “Yes.” So he said: I heard you grandfather Ja’far bin Muhammad (as) say: There will not be an Imam unless he has descendants. So he (as) said: “Did you forget, O Sheikh (old person), or did you try to forget? This is not what Ja’far (as) said, rather Ja’far (as) said: There will not be an Imam unless he has descendants, except the Imam that alHussain bin Ali (as) emerges to, he has no descendants.” So he said to him (as): You have told the truth, may I be your ransom, this is what I heard your grandfather saying.
Ghaiba alTusi, p.224, Hadith.188: From alHasan bin Ali alKhazaz, he said: I entered to Ali ibn Abi Hamza who was with Abi alHasan alRidha (as), he told him (as): Are you an Imam? He (as) said: “Yes.” So he said: I heard you grandfather Ja’far bin Muhammad (as) say: There will not be an Imam unless he has descendants. So he (as) said: “Did you forget, O Sheikh (old person), or did you try to forget? This is not what Ja’far (as) said, rather Ja’far (as) said: There will not be an Imam unless he has descendants, except the Imam that alHussain bin Ali (as) emerges to, he has no descendants.” So he said to him (as): You have told the truth, may I be your ransom, this is what I heard your grandfather saying.
.Imam Al Saadeq pbuh said:”After the Riser there will be 12 Mahdis from the son of Hussein” p.385/Burhan v.3 p.310/Bihar AlAnwar v.53 p.148
Imam Al Saadeq pbuh said:”After the Riser there will be 11 Mahdis from the son of Hussein” Mukhtasar Basa’er AlDarajat p.38 Gaibat AlToosi p.478/Bihar AlAnwar v.53 p.145
Imam Hussain a.s. isn’t a son of himself or even Imam Ali a.s. or even Imam Hasan a.s. in these above hadeeths