Al-Matalib al-'Aliyah 4146 — Banu Amir and Banu Tamim

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) was asked about the various tribes of the Arabs. The narrator said: On that day either he (peace and blessings be upon him) could not attend to them, or they were unable to gain his (peace and blessings be upon him) attention; however, they asked about three tribes. When they asked about Banu Amir, he (peace and blessings be upon him) said: "They are like a bright white camel that grazes on the edges (the choicest parts) of the trees." When they asked about Ghatafan, he (peace and blessings be upon him) said: "It is a blossom from which a spring of water gushes forth." And when they asked about Banu Tamim, he (peace and blessings be upon him) said: "They are like a hard red hill; whoever takes up enmity against them or speaks ill of them will not be able to harm them." Then the Prophet (peace and blessings be upon him) further said: "Allah Almighty has refused anything but good for Banu Tamim; they are people of large heads (of great intelligence and understanding), of weighty minds, and firm of foot on the battlefield. They will be the fiercest of people in fighting against the trial of the Dajjal, and the helpers and supporters of the truth in the last age."
This narration is in the Musnad of al-Harith (Bughyat al-Bahith); its chain contains a narrator named Zayd al-Ammi, who is da'if (weak). However, the mention of Banu Tamim being severe against the Dajjal and their other virtues is also explicitly found in authentic hadiths of Sahih al-Bukhari and Sahih Muslim.