"The worst of all people lying is a man who trades insults with another man, disparaging the entire tribe, and a man who denies his father and accuses his mother of adultery." (Using translation from Ibn Mājah 3761)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ أَعْظَمِ النَّاسِ فِرْيَةً لَرَجُلٌ هَجَا رَجُلًا فَهَجَا الْقَبِيلَةَ بِأَسْرِهَا وَرَجُلٌ انْتَفَى مِنْ أَبِيهِ وَزَنَّى أُمَّهُ