Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyidah Aisha (may Allah be pleased with her), she says that the Messenger of Allah (peace and blessings be upon him) said: "The greatest criminal in making false accusations is the one who wants to mention the faults of a man, but he condemns his entire tribe, and there is also the man who denies his (real) father and declares his mother to be an adulteress."