It is related with a sound chain of authority from Salman al- Farsi, 'I visited the Messenger of Allah who looked at me and said,
"O Salman, Allah does not send a prophet or messenger unless there are with him twelve chiefs."
“O Messenger of Allah, I know this from the people of the two books.”
"O Salman, do you know my twelve chiefs, whom Allah has chosen to be leaders after me?"
"Allah and His Messenger know best."
"O Salman, Allah created me from the quintessence of light, and called me, so I obeyed Him. Then He created 'Ali from my light, and called him, and he obeyed. From my light and the light of 'Ali He created Fatimah: He called her and she obeyed. From me, 'Ali and Fatimah, He created al-Hasan and al-Husayn. He called them and they obeyed Him. Allah has named us with five of His names: Allah is al-Mahmud (the Praised) and I am Muhammad (worthy of praise); Allah is al-'Ali (the High), and this is 'Ali (the one of high rank); Allah is al-Fatir (Creator out of nothing), and this is Fatimah; Allah is the One with Hasan (beneficence), and this is Hasan; Allah is Muhassin (the Beautiful), and this is Husayn. He created nine Imams from the light of al-Husayn and called them and they obeyed Him, before Allah created either Heaven on high, the outstretched earth, the air, the angels or man. We were lights who glorified Him, listened to Him and obeyed Him."
"O Messenger of Allah, may my father and mother be your ransom! What is there for the person who recognizes these men as they should be recognized?"
"O Salman, whoever recognizes them as they should be recognized, and follows their example, befriends them and is free of their enemies, by Allah! he is one of us. He will return to where we return, and he will be where we are!"
"O Messenger of Allah, is there belief without knowing their names and lineage?"
"Messenger of Allah, where will I find them?"
"You already know al-Husayn; then there will be the master of the worshippers, 'Ali ibn Husayn (Zayn al-'Abidin); then his son Muhammad ibn 'Ali, the piercer of the knowledge of the early and the later prophets and messengers (al-Baqir); then Ja'far ibn Muhammad, the truthful tongue of Allah (al-Sadiq); then Musa ibn Ja'far, the one who kept his rage silent through patience in Allah (al-Kadhim); then 'Ali ibn Musa, pleased with the secret of Allah (al-Rida '); then Muhammad ibn 'Ali, the chosen one from the creatures of Allah (al-Mukatar); then 'Ali ibn Muhammad, the guide to Allah (al-Hadi); then al-Hasan, son of 'Ali, the silent, trustworthy guardian over the secret of Allah (al-'Askari); then mim ha' mim dal (Muhammad), called Ibn al-Hasan, the announcer who establishes the right of Allah."
Salman said, 'I wept. Then I continued,
"O Messenger of Allah, let my life be deferred until their time! "’
'He said, "O Salman, recite this:
فَإِذَا جَاء وَعْدُ أُولاهُمَا بَعَثْنَا عَلَيْكُمْ عِبَادًا لَّنَا أُوْلِي بَأْسٍ شَدِيدٍ فَجَاسُواْ خِلاَلَ الدِّيَارِ وَكَانَ وَعْدًا مَّفْعُولاً
ثُمَّ رَدَدْنَا لَكُمُ الْكَرَّةَ عَلَيْهِمْ وَأَمْدَدْنَاكُم بِأَمْوَالٍ وَبَنِينَ وَجَعَلْنَاكُمْ أَكْثَرَ نَفِيرًا
"I wept a lot," said Salman, "and my yearning became intense.” I said, "O Messenger of Allah, is it a pledge from you?"
' "Yes, by the One Who sent me and entrusted me with the Message; it is a pledge from me and from 'Ali, Fatimah, al-Hasan, al-Husayn, and the nine Imams descended from the children of al-Husayn, to you and those who are with us, and those of us who are wronged. Whoever is truly sincere in his belief, then by Allah, Salman, let Iblis and his armies come. Whoever has pure disbelief will be punished by retaliation, torture and inheritance (i.e. by others rather than them). Your Lord will not wrong anyone. It is we who are indicated in this verse:
وَنُرِيدُ أَن نَّمُنَّ عَلَى الَّذِينَ اسْتُضْعِفُوا فِي الْأَرْضِ وَنَجْعَلَهُمْ أَئِمَّةً وَنَجْعَلَهُمُ الْوَارِثِينَ. وَنُمَكِّنَ لَهُمْ فِي الْأَرْضِ وَنُرِي فِرْعَوْنَ وَهَامَانَ وَجُنُودَهُمَا مِنْهُم مَّا كَانُوا يَحْذَرُونَ
Salman said, “I took leave of the Messenger of Allah, completely unconcerned as to how Salman would meet death, or how death would meet him.”