The Book of Occultation — al-Ṭūsī · Hadith 508 (#Ḥadīth #7)
Chapter 39 | Test of Shia during the period of occultation of the Imam
287- وروي عن جابر الجعفي قال: قلت لأبي جعفر عليه السلام: متى يكون فرجكم؟ فقال: هيهات هيهات! لا يكون فرجنا حتى تغربلوا ثم تغربلوا ثم تغربلوا، يقولها ثلاثا، حتى يذهب (الله تعالى) الكدر ويبقى الصفو.
H 287 - It is narrated from Jabir Jofi that he said: I asked Imam Muhammad Baqir : “When will you come to power?” He replied: “It’s a pity that it will not be so till you are all sieved like grain is sieved to separate it from chaff. And then you are sieved again and again, till there does not remain any impurity and only the clean grain is left.”
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).