It is narrated from Sayyiduna Abu Umamah bin Tha'labah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever takes as his patrons (mawali) others than his true patrons (the masters who freed him), upon him is the curse of Allah, of the angels and of all people; Allah Almighty will accept from him neither an obligatory nor a voluntary deed. And whoever introduces some new mischief or innovation in this city of mine (Madinah), or gives refuge to one who causes mischief and innovates, upon him is the curse of Allah, of the angels and of all people; neither an obligatory nor a voluntary deed will be accepted from him."
This hadith is not narrated from Sayyiduna Abu Umamah bin Tha'labah (may Allah be pleased with him) except with this chain, in the narration of which Abdullah bin al-Munib is alone.
Hadith Referenceالمعجم الأوسط / باب الألف / 193
Hadith Gradingمحدثین:فيه عبد الله بن عطية لم يروِ عنه إلا منيب، وبقية رجاله ثقات
Hadith Takhrij«قال الهيثمي: فيه عبد الله بن عطية وقال الذهبي لا أعلم من روى عنه إلا منيب وبقية رجاله ثقات «مجمع الزوائد ومنبع الفوائد، ج 4، ص 232»» «أخرجه النسائي فى «السنن الكبرى» برقم: 5974، والطبراني فى «الكبير» برقم: 795»