Hazrat Imam Mahdi (as) bears the special characteristics and more from the previous prophets. He is the embodiment of their virtues and qualities. He carries their signs and is the inheritor of all that they stood for and what was revealed upon them. The following article mentions the similarity between Hazrat Ishaq (as) and Imam Mahdi (as).
Special birth
Almighty Allah gave the glad tidings of Hazrat Ishaq’s (as) birth to Sara when she had lost all hope of having a child. Allah, the Mighty and Sublime says, “And his wife was standing (by), so she laughed, then We gave her the good news of Ishaq and after Ishaq of Yaqoob. She said, O wonder! shall I bear a son when I am an extremely old woman and this my husband an extremely old man? Most surely this is a wonderful thing.” (Chapter 11 verses 71-72)
Imam Mahdi (as) is also such that when people became despaired that he would be born, they were given the glad news of his birth.
As mentioned in Kharaij quoting from Isa bin ash-Shaykh (or Masih) that he said, Imam Hasan Askari (as) came to us in the prison. I was cognizant of his rights (considered him my Imam). He told me, You are aged 65 years, one month and two days. I had a prayer book with me on which my date of birth was written. When I referred to it I saw that what the Imam had said was right.
Then he asked, Do you have children? ‘No,’ I replied. He raised up his hands in prayer and said, O Allah, bestow him a son who may become his support as a son is a very good support. Then he recited the flowing couplets to illustrate his point, Whoever has an arm will take back his usurped rights Indeed, disgraced is one who does not have an arm.
I asked Imam Askari (as), Do you have a son? He replied, Yes, by Allah, I would have a son who would fill up the earth with justice and equity; however, presently I am not having a son. Then he continued his recitation of couplets, Perhaps that day arrives when you will see my son besides me like a lion cub. Thus indeed, before the Teem give birth to many children for a long period of time he was alone among the people. (Kharaij, page 72)
(The above article was taken and adapted from the book Mikyalul Makarim Fee Fawaedid Dua Lil Qaem)