To what extent is the noble Hadith sound: "Usury has seventy-odd levels, the lowest of which is for a man to commit adultery with his mother in the Sacred House, and the highest of which is for a Muslim man to harm his Muslim brother"?

Usury has seventy doors, the easiest of which is like a man marrying his mother. It has been narrated from the Prophet, peace and blessings be upon him, traditions indicating that the most severe type of usury is for a man to violate the honor of his Muslim brother, meaning through insults, curses, and slander.

Other traditions have been narrated indicating that backbiting is more severe than fornication, because the fornicator may repent and Allah will accept his repentance, whereas the backbiter will not be forgiven unless the person whose rights were violated forgives him. This indicates that the severity of backbiting over fornication is not absolute, but rather from the perspective that repentance for it is not sufficient unless the person whose rights were violated grants forgiveness, unlike fornication for which sincere repentance suffices.