What is Narrated From Al-Askari عليه السلام Regarding the Designation of Al-qa'im

And through the same chain of narrators he said: Abul Hasan Ali bin Musa ar-Reza عليه السلام said: “When the Prophet صلى الله عليه وعلى آله وسلم passed away from this world and calamities came down on the holy Ahlul Bayt عليه السلام at that time Amirul Momineen, Fatima, Hasan and Husain عليه السلام were present in the room in which the holy body of the holy Prophet صلى الله عليه وعلى آله وسلم was laid. Suddenly there came a voice, “Assalaamu alaikum O Ahlul Bayt! Every living being will taste the taste of death. Your reward will be given fully to you in the Qiyamat. If anyone dies, verily, Allah is his substitute and successor Who provides patience in every calamity and He is the remover of its harm. He compensates every loss. So rely only on Him because the (real) loser is he who loses the reward of Allah.” Amirul Momineen عليه السلام said, “He (the invisible speaker) is my brother Khizr عليه السلام. He has come to condole you on the death of your Prophet صلى الله عليه وعلى آله وسلم.”