Bismillah, nothing but an article straight from shia site:

Zakariya bin Adam narrates:

و أخبرني أبو الحسن محمد بن هارون بن موسى قال حدثنا أبي قال أخبرني أبو جعفر محمد بن أحمد بن الوليد قال حدثنا محمد بن أحمد بن أبي عبد الله البرقي قال حدثنا زكريا بن آدم قال إني لعند الرضا إذ جي‏ء بأبي جعفر له و سنه أقل من أربع فضرب بيده إلى الأرض و رفع رأسه إلى السماء و هو يفكر فقال له الرضا بنفسي أنت لم طال فكرك فقال فيما صنع بأمي فاطمة أم و الله لأخرجنهما ثم لأحرقنهما ثم لأذرينهما ثم لأنسفهما في اليم نسفا فاستدناه و قبل ما بين عينيه ثم قال أنت لها يعني الإمامة

“Once I was with Imam Reza (as) that Aba Jafar Imam Muhammad Taqi (as) came. His (as) age was less that 4 years. He (as) struck his hands on the ground and raised his head towards the sky and thought for long.”

Then Imam Reza (as) said, “By my self, What are you thinking for so long?”

Imam Taqi (as) said, “I am thinking regarding my (grand) mother Fatema (sa). By Allah (swt), I want to remove those two (abu bakr and umar), burn those two and blow away their remains in the sea.”

Imam Reza (as) then kissed him between his eyes (on the forehead) and said, “My father and mother be sacrificed for you. For you is the Imamate.”

[Source: Bihar al Anwar vol.50 pg.59 / Dalail Al Imamah Pg.212]

Note: This is a long hadees, only a part is being quoted here.

Amir Al Momineen (as) narrates that Prophet Muhammad (saww) said:

“On the night of Me’raj……”

فقال عز و جل ارفع رأسك فرفعت رأسي و إذا أنا بأنوار علي و فاطمة و الحسن و الحسين و علي بن الحسين و محمد بن علي جعفر بن محمد و موسى بن جعفر و علي بن موسى و محمد بن علي و علي بن محمد و الحسن بن علي و م‏ح‏م‏د بن الحسن القائم في وسطهم كأنه كوكب دري ‏قلت يا رب و من هؤلاء قال هؤلاء الأئمة و هذا القائم الذي يحلل حلالي و يحرم حرامي و به أنتقم من أعدائي و هو راحة لأوليائي و هو الذي يشفي قلوب شيعتك من الظالمين و الجاحدين و الكافرين فيخرج اللات و العزى طريين فيحرقهما فلفتنة الناس يومئذ بهما أشد من فتنة العجل و السامري

“Allah (swt) said, “Raise your head”.

I raised my head and saw My light along with the light of Ali, Fatema, Hasan, Husain, Ali bin Husain, Muhammad bin Ali, Jafar bin Muhammad, Musa bin Jafar, Ali bin Musa, Muhammad bin Ali, Ali bin Muhammad, Hasan bin Ali, MHMD bin Hasan Al Qaim (peace be upon them all) in the center amongst them like a shining star.

I (saww) said, “O Lord, Who are these?”

Allah (swt) said, “These are the Imam’s (as) and this is Al-Qaim (atfs) who will establish my halaal as halaal and my haraam as haraam. And by Him (atfs) I will take revenge from my enemies. He (atfs) is the source of rest for my friends. He (atfs) is the one who will heal the hearts of the Shia’s from the oppressors, deniers and disbelievers. He (atfs) will remove ‘Laat’ and ‘Uzza’ (referring to Abu bakr and Umar) and burn both of them. The Fitna/Affliction of that day will be more severe than the fitna/affliction of calf and samarri.

[Source: Kamal ud Deen (sheikh Saduq) Vol.1 Pg.253]

Abu Mansur Al-Tabrasi narated from Abdul Adheem al Hasani:

I said to Imam Jawad : My master…(Abdul Adheem has a conversation with the Imam about Imam Al-Mehdi but I dont want to write all of it as only one portion is relevant)

فإذا اجتمعت له هذه العدة من أهل الإخلاص، أظهر الله أمره، فإذا كمل له العقد وهو: (عشرة آلاف) رجل خرج بإذن الله، فلا يزال يقتل أعداء الله حتى يرضى عز وجل.قال عبد العظيم: فقلت له: يا سيدي فكيف يعلم أن الله قد رضي؟ قال: يلقي في قلبه الرحمة، فإذا دخل المدينة أخرج اللات والعزى فأحرقهما

(Imam Jawad speaking): Allah will make him appear to the people after these (the 313) men will have joined him. He will rise with the permission of Allah after his army of 10,000 men will have formed, and he will continue killing the enemies of Allah untill Allah is pleased with him.

I (Abdul Adheem) asked: How will he know Allah is pleased with him?

Imam replied, “Allah will place the mercy in his heart. Then he will enter Medina, and he will exhume Laat and Uzza (from their graves), and he will burn them.”

[Source: Al Ihtijaj (2:249) Al-Tabrasi & Al Mahajjah (pg 15-16) Al-Bahraini]