It will suffice here to quote...
It will suffice here to quote, as an example, a few of these traditions: When Imam Hasan al-Mujtaba (a.s.) held the seat of the caliphate, he fought the hypocritical Mu’awiyyah, who, with the assistance of his cunning minister, gradually deceived the companions of Imam Hasan (as.), who thus deserted and left the Imam alone.
Hence, he was compelled to make a peace treaty with Mu’awiyyah in which lie (Mu’awiyyah) was obliged to comply with some duties and to refrain from appointing a successor and fighting. On some occasions, the Imam took the opportunity to point out to the people Mu’awiyah's errors and unjust acts. Meanwhile, some of ignorant people started criticising the Imam as to why he had accepted the peace treaty!
Imam Hasan (a.s.) clarified for the people the meaning of the Imam and the leader, and the necessity of obeying every command of the Imam without asking why and wherefore.
Then he explained to them about the Government of the Twelfth Imam saying: "Don’t you know that every one of us (Imams) has the responsibility of taking allegiance from the oppressors of his time, except the ‘Support’ (al-Qa'im) behind whom the Spirit of Allah (Jesus) will pray; and Almighty Allah will keep secret his birth from some people and will conceal his person from their sights. When he appears he will not be responsible for taking allegiance from anyone.
He is the ninth descendant of my brother Husayn, the son of the captive princess. Almighty Allah will pro-long his age during his occultation, and by His Perfect , he will appear as a young man of less than forty years so that all people will know that Allah truly has power over all things.
Imam Ja’far as-Sadiq (a.s) in reply to a question from one of his followers about his successors, said: "The Imam succeeding me is my son Musa, and the Awaited Imam is Muhammad ibn Hasan ibn ‘All ibn Muhammad ibn ‘Ali ibn Musa.
The same Imam is quoted as having said repeatedly that: "Every group of people is waiting for a government and we are waiting for our Government to be established at the End of Time." The Seventh Holy Imam Musa ibn Ja’far (a.s.) in a reply to one of his companions who asked him whether he was "al-Qa'im bi ‘1-Haqq" (he who is supported by the Truth), said: "I am al-Qa’im bi’l-Haqq, but that ‘al- Qa'im who will remove Allah's enemies from the earth and will fill it with justice and equity is my fifth descendant.