What should one do if someone is witness of someone’ Zina, theft or slandering of adultery? Should we advise them to repent and return the rights of others or report them? And the person agrees to repent and fulfill all conditions of repentance.
Advise the parties involved that they committed an enormous sin and that they should stop it, repent from it and return whatever rights they violated through it. Remind them of the punishment Allah promised in this world and the next for those who do such things but do not expose them if they took care to conceal themselves. The Prophet (upon him
blessings and peace) said: “Whoever covers up a Muslim [= his/her fault], Allah will cover him up in this world and the next” as narrated from Abu Hurayra, Ibn `Umar and others in the two Sahihs, the Sunan and the Musnad.
Hajj Gibril Haddad