Allah the Exalted said:
٢٧٥ - باب تحريم الطعن في الأنساب الثابتة في ظاهر الشرع
Allah the Exalted said:
And those who harm believing men and believing women for [something] other than what they have earned [i.e., deserved] have certainly borne upon themselves a slander and manifest sin.
Abū Hurayra (may Allah be pleased with him) said: The Messenger of Allah ﷺ said: "Two things found among people are disbelief on their part: disparaging lineage, and wailing over the dead." Narrated by Muslim.