الكافي 1/4/83/2

2. Muhammad Yahya and al-Hassan ibn Muhammad have narrated from al-Qasim ibn ’Isma‘il al-Anbari from al-Husayn ibn Ali from abu al-Mighra’ from abu Yah Ya‘fur who has said the following. “I heard abu ‘Abdallah عليه السلام say as herein below, ‘Woe to the rebellious Arabs from the matter that is coming closer.’0” I then asked, May Allah take my soul in service for your cause, “How many people will be there with Al-Qa’im (the one who will rise with Divine Authority)?” The Imam عليه السلام said, “just a very few persons.” I then said, “Those who speak of this matter (the rise of al-Mahdi with Divine Authority) are quite many in number.” The Imam عليه السلام said, “People must be refined, distinguished and sifted. In the sifting process a great deal is taken out.”