Masadeh says, I was with Imam Jafar as-Sadeq (a.s.), when suddenly an old man with an arched back walked in, leaning on his stick. He conveyed his salam to Imam (a.s.) and Imam (a.s.) answered him.
The old man said, O son of the Messenger of God (a.s.), give me your hand so I can kiss it, so he (a.s.) gave him his hand and he kissed it and then wept.
Imam (a.s.) asked him: O Shaikh! Why are you crying?
He replied, may I be your ransom. I have been waiting for Qaem (a.t.f.s.) for the last hundred years. I keep saying that it will (reappearance) take place in this month and this year.
But my age is advancing and my bones are getting brittle and my death is nearing. But I do not like to see you sick, far from home, and your enemies flying with their wings, so how can I not cry?
Imam Sadeq (a.s.)’s eyes welled up and he said: O Shaikh! If Allah keeps you alive till you see our Qaem, you will be at the highest level with us. And if death befalls you (and you do not see the Imam), you will come with the weight of Muhammad (s.a.w.a.) and we are his weight.
He (s.a.wa.) said, “I leave among you two weighty things, so hold on to themto, and if you cling to them, you will never go astray. Those two precious gems are the Book of Allah and my progeny, that is, my family.”
After hearing this, the old man said, “After hearing this news, I am no longer afraid of dying.”
Imam Sadeq (a.s.) continued:
O Shaikh! Indeed, our Qaem is the offspring of Hasan (Askari), Hasan is the offspring of Ali(an-Naqi), Ali is the offspring of Muhammad (al-Jawwad), Muhammad is the offspring of Ali (ar-Raza) and Ali is the offspring of my son Musa (al-Kazim), peace be upon them all. And at this time, he pointed to him and said: Musa has also come out of my loin.
We are Ahl al-Bayt, the twelve people, all of whom are infallible and purified.”
Ref: Kifayatul Asar 264-265