Long lifespan of the Imam عليه السلام
Kitāb al-Ghayba|Volume 1|Book 1|Chapter 49
وأما ما روي من الاخبار التي تتضمن أن صاحب الزمان يموت ثم يعيش أو يقتل ثم يعيش، نحو ما رواه:
Reports, which mention that the Imam of the Age will pass away or would be martyred and after that he would become alive again: