Ghaibat Nomani: It is narrated from Ahmad bin Idris from Ibne Qutaibah from Ibne Shazan from Ahmad bin Abi Nasr Bazanti that he said: Imam Musa Kazim (a.s.) said:
By Allah, that to which you look forward to [Mahdi], will not come about except after you are distinguished and you are subjected to a test till except for a few will remain:
“What! Do you think that you will be left alone while Allah has not yet known those of you who have struggled hard and have not taken anyone as an adherent besides Allah and His Apostle and the believers…” (Surah Taubah 9:16)
[The Promised Mahdi, Allamah Muhammad Baqir al-Majlisi, Biharul Anwar, Volume 13 (Old Edition)/Volumes 51-52-53 (New Edition)]