Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) narrated that the Prophet (peace and blessings be upon him) said: "The Hour will not be established until a man from among my Companions is searched for just as a lost thing is searched for, and then he is not found." (The narrator is in doubt about one word here.)
Imam Ahmad and Imam al-Bazzar recorded it. Its chain contains a narrator, al-Harith al-A'war, and he is da'if (weak), and despite his weakness he has been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16399
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه البزار فى المسند (2775 و 2772) اخرجه احمد فى المسند (720 و 675) ، أخرجه مسند أحمد برقم: 677»