Habbah said: Once Sayyiduna Hudhayfah (may Allah be pleased with him) and Sayyiduna Abu Mas'ud (may Allah be pleased with him) met, and one of the two said to the other: The Prophet (peace and blessings be upon him) said: "A rebellious group will kill Ammar." And the other confirmed it.
Al-Bazzar recorded it; its chain contains Muslim al-Mula'i, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15617