"اثنان في الناس هما بهم كفر: الطعن في النسب، والنياحة على الميت"
Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah (ﷺ) said, "Two things are signs of disbelief on the part of those who indulge in them: Slandering one's lineage and wailing over the dead." [Muslim] .