Is it permissible to speak well or ill of someone, or to spy on him and listen to his conversations, or to take his personal belongings, if he has given permission and forgiveness for all these matters?

Backbiting and spying are forbidden by the Quran, Sunnah, and scholarly consensus, as Allah the Almighty says: "O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin. And do not spy or backbite each other." And the Prophet, peace and blessings be upon him, said: "Do not spy and do not eavesdrop."

It is permissible for a person to absolve another of financial obligations and to forgive them for transgressing their honor, thus waiving the right of that person. However, the right of Allah remains if the person does not repent and seek Allah's forgiveness.

Waiver and forgiveness are beneficial for financial matters or for transgressions that have already occurred. However, permitting the violation of one's honor in the future is not permissible, because it would be a permission for backbiting, spying, and insults, which are forbidden by Islamic law.

What was asked about is considered backbiting and spying, and these are not permissible even if the person whose rights are affected gives permission. As for money, its owner is permitted to absolve another of it if the giver's soul is content with that.