HAZRAT MAHDI (PBUH) WILL BE YOUNG IN APPEARANCE DESPITE HIS AGE
Aba Salte Haravi I asked Imam Reza (a.s.):
“What is the sign of your Qaim [Mahdi (pbuh)] (so that one can recognize him)?”
Hazrat Reza (a.s.) replied:
“Amongst the signs is that he would be old age, but would look young in appearance. Anyone looking at him would imagine him to be forty or even less. Amongst his other sign is that time would never turn him old until death meets him.”
In another tradition, Imam Hasan-ibn-Ali (a.s.) says:
"When Mahdi (pbuh) will rise, the people would deny him because he would approach them with the face of a youth, while they would imagine him to possess an aged face."
(Remembrance of The Beloved: Questions and Answers about Imam Mahdi (pbuh), Seyed Husain Husaini, page 48)