It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) used to say: There are two practices from the time of ignorance which people will never abandon: one is wailing (over the dead) and the other is casting aspersions on someone's lineage.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 9574
Hadith Gradingحکم دارالسلام:حدیث صحیح ، وھذا إسناد قوي