It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever is killed under a blind banner of unclear purpose, while fighting merely out of tribal partisanship or helping someone merely on the basis of partisanship, his being killed is a death of Jahiliyyah (pre-Islamic ignorance)."
No one narrated this hadith from Suwayd bin Hujayr (may Allah have mercy on him) except al-Hajjaj bin al-Hajjaj al-Bahili (may Allah have mercy on him), and Qaza'ah bin Suwayd (may Allah have mercy on him) is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الألف / 416
Hadith Gradingمحدثین:إسناده ضعيف لضعف قزعة بن سويد
Hadith Takhrij«قال الهيثمي: فيه قزعة بن سويد وهو ضعيف وقد وثق «مجمع الزوائد ومنبع الفوائد، ج 6، ص 286»» «أخرجه الطبراني فى «الأوسط» برقم: 3946»