Assalam O Alaikum, Wa Rehmatullah, Wa Barakatuhu.
Question: What will happen after your 12th Imam? Or who will be the 13th Imam after him?
As it is written in your books that he will rule for some period then will die before his shias and earth will exist for a long time even after him. Below are all possible options for his period of rule from your books.
“His rule will be seven years and each year is equivalent to ten of your years. Therefore, the years of his rule will be equivalent to your seventy years.”
• Shaykh al-Mufid, Al-Irshad, p. 363; Shaykh at-Tusi, Ghaybah, p. 283; Rawdah al-Wa‘izin, vol. 2, p. 264; Sirat al-Mustaqim, vol. 2, p. 251; Al-Fusul al-Muhimmah, p. 302; Al-Ayqaz, p. 249; Bihar al-Anwar, vol. 52, p. 291; Nur ath-Thaqalayn, vol. 4, p. 101.
• ‘Iqd ad-Durar, pp. 224, 238; Ithbat al-Hudah, vol. 3, p. 624.
The Holy Messenger of Allah (S) said: “The Mahdi (‘atfs) is from us… and for seven years he will take charge of affairs.”
• Al-Fusul al-Muhimmah, p. 302; Ibn Batriq, ‘Umdah, p. 435; Dala’il al-Imamah, p. 258; Hanafi, Burhan, p. 99; Majma‘ az-Zawa’id, vol. 7, p. 314; Fara’id as-Simtayn, vol. 2, p. 330; ‘Iqd ad-Durar, pp. 20, 236; Shafi‘i, Bayan, p. 50; Hakim, Mustadrak, vol. 4, p. 557; Kanz al-‘Ummal, vol. 14, p. 264; Kashf al-Ghummah, vol. 3, p. 262; Yanabi‘ al-Mawaddah, p. 431; Ghayah al-Maram, p. 698; Bihar al-Anwar, vol. 51, p. 82.
The Prophet (S) also said: “He will rule for seven years over this ummah.”
• ‘Iqd ad-Durar, p. 20; Bihar al-Anwar, vol. 51, p. 82.
The Messenger of Allah (S) also said elsewhere: “The tenure of rule of al-Mahdi (S) will be seven years at the shortest or it will last for eight or nine years at the longest.”
•Ibn Tawus, Malahim, p. 140; Kashf al-Astar, vol. 4, p. 112; Majma‘ az-Zawa’id, vol. 7, p. 314.
It has also been reported: “Hadrat al-Mahdi (‘atfs) will rule in this world for nine years.
• Ibn Tawus, Tara’if, p. 177.
Jabir ibn ‘Abdullah al-Ansari asked Imam al-Baqir (‘a): “How many years will the Imam of the Time (‘atfs) live?” The Imam (‘a) replied: “From the day of the uprising till his demise will be nineteen years long.
• ‘Ayyashi, Tafsir ‘Ayyashi, vol. 2, p. 326; Nu‘mani, Ghaybah, p. 331; Ikhtisas, p. 257; Bihar al-Anwar, vol. 52, p. 298.
The Messenger of Allah (S) said: “Hadrat al-Mahdi (‘atfs) will rule for twenty years. He will take out the treasures from the ground; he will conquer the lands of polytheism.”
• Firdaws al-Akhbar, vol. 4, p. 221; Al-‘Ilal al-Mutanahiyyah, vol. 2, p. 858; Dala’il al-Imamah, vol. 233; Ithbat al-Hudah, vol. 3, p. 593; Bihar al-Anwar, vol. 51, p. 91. See Tabrani, Mu‘jam, vol. 8, p. 120; Asad al-Ghabah, vol. 4, p. 353; Fara’id as-Samtayn, vol. 2, p. 314; Majma‘ az-Zawa’id, vol. 7, p. 318; Lisan al-Mizan, vol. 4, p. 383.
He (S) also said: “The Mahdi (‘atfs) is from my progeny and he will rule for twenty years.”
•Kashf al-Ghummah, vol. 3, p. 271; Ibn Batriq, ‘Umdah, p. 439; Bihar al-Anwar, vol. 51, p. 1; Ibn Tawus, Malahim, p. 142; Firdaws al-Akhbar, vol. 4, p. 6; Dala’il al-Imamah, p. 233; ‘Aqd ad-Durar, p. 239; Yanabi‘ al-Mawaddah, p. 432.
It has also been reported: “The Imam (‘atfs) will rule for ten years.”
• Nur al-Absar, p. 170; Ash-Shi‘ah wa’r-Raj‘ah, vol. 1, p. 225. See Fadl al-Kufah, p. 25; A‘yan ash-Shi‘ah, vol. 2, p. 51; Yanabi‘ al-Mawaddah, p. 492.
In answer to the question on how many years the Mahdi (‘atfs) will rule, Hadrat ‘Ali (‘a) said: “He will rule over the people for thirty or forty years.”
•Ibn Hammad, Fitan, p. 104; Kanz al-‘Ummal, vol. 14, p. 591.
Imam as-Sadiq (‘a) said: “Hadrat al-Mahdi (‘atfs) will be from my progeny and his age will be equal to that of Ibrahim Khalil ar-Rahman (Prophet Abraham) (‘a). He will appear at the age of eighty years and rule for forty years.”
•Ithbat al-Hudah, vol. 3, p. 574
The same Imam (‘a) also said: “The tenure of Hadrat al-Qa’im’s (‘atfs) rule will be nineteen years and some months.”
•Nu‘mani, Ghaybah, p. 331; Bihar al-Anwar, vol. 52, p. 298; vol. 53, p. 3.
Imam al-Baqir (‘a) said: “Hadrat al-Qa’im (‘atfs) will rule for three hundred and nine years just as the Companions of the Cave stayed in the cave for the same period.”
•Shaykh at-Tusi, Ghaybah, p. 283; Bihar al-Anwar, vol. 52, p. 390; Ithbat al-Hudah, vol. 3, p. 584.