Sayyiduna Samurah bin Jundub (may Allah be pleased with him) states: the Prophet (peace and blessings be upon him) said: "The people of Banu Ghifar and of the tribe of Aslam are a trial for many people. Those people say: 'If this were something good, Allah Almighty would not have placed these people first among (all the other) people.' Indeed, may Allah Almighty forgive the people of the tribe of Ghifar, and may Allah Almighty keep the people of the tribe of Aslam safe."
Al-Tabarani recorded it, and al-Bazzar recorded it from that Companion in abridged form. The chain of al-Bazzar contains Yusuf bin Khalid al-Samti, who is da'if (weak), and the chain of al-Tabarani contains a narrator whom I do not know.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16563
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (7096)»