Will the Mahdi die and return to dunya (Raj’a)?

Introduction: 

Shi’i narrations indicate that after the Mahdi is killed, all the previous Imams will come back to dunya before the Day of Judgement to enact on earth - as part of the phenomenon is known as Raj’a. 

However, will the Mahdi also return to life after his death before the Day of Judgement?

The following hadith in al-Ghayba by al-Tusi, volume 1, page 491 clarifies:

Hadith:

“Narrated Abi Sa’id al-Khurasani: I asked Abi Abdilah [al-Sadiq] عليه السلام: 

Are the Mahdi and the Qa’im one [person]? 

He [al-Sadiq] said: ‘Yes’

So I [narrator] asked him: For what reason was he [i.e, the Twelfth Imam] called the Mahdi? 

He [al-Sadiq] said: Because he guides to every hidden matter. And he was called al-Qa’im because he will rise after his death and he will preside over a great matter. [i.e, he will return to dunya affer his death to enact justice].

489 - عنه، عن موسى بن سعدان، عن عبد الله بن القاسم الحضرمي، عن أبي سعيد الخراساني قال: قلت لأبي عبد الله عليه السلام: المهدي والقائم واحد؟.

فقال: نعم.

فقلت: لأي شئ سمي المهدي؟.

قال: لأنه يهدي إلى كل أمر خفي، وسمي القائم لأنه يقوم بعدما يموت، إنه يقوم بأمر عظيم (4).

Evaluation:

The concept of Raj’a (returning to dunya before the day of Judgement) was one of the most distinctive features of the early Imamiyya Shi’a, and which set them apart from other sects. 

Being so, each one of our Imams is labeled a Qa’im in our scripture. This appellation has direct connotations of Raj’a, implying that our Imams will enact the ultimate justice by returning to life on Earth after dying. And this will happen before Yawm al-Qiyama.