Ibn Hajar al-Hatamy says that Imam Hassan al-Askari (as) Had a son called Muhammed.
Ibn Hajar al-Hatamy says in his book "Sawa'eq al-Muhriqa" on page 314, beriut print, lebanon, Dar al-Kutub al-Elmiya:
" .....till he (Imam Hassan) died in sir man ra'a, and he was buried next to his father and his uncle, at the age of 28. It was said that he was piosned. And he left behind him his only son: Abul Qassim Muhammed al-Hujjah, his age was five when his fathe passed away, but Allah bestowe upon him wisdom and he was named al-Qassim al-Muntazar (the awaited one), it was said because he hid himself in Madina and went away and it not known where he had gone, and we mentioned in the chapter of the 12th verse that the Rafida said he is the Mahdi, I mentioned that briefly, read over it, its important"
Scans from "Sawa'eq al-Muhriqa" for Ibn Hajar al-Hatamy
