Is it permissible to kill a man caught in the act of adultery with one's mother, in defense of honor, after more than 30 years have passed since the incident, or should the matter be concealed?

The neighbor must conceal what he has seen and not disclose it to anyone, seeking reward from Allah, for the Prophet, peace and blessings be upon him, said: "Whoever conceals a Muslim, Allah will conceal him on the Day of Resurrection." As for him throwing his mother out or killing her merely based on an accusation or suspicion, without legal proof, this is not permissible for him. The honor and blood of Muslims are of greater significance to Allah than to be violated based solely on doubt. His action does not stem from permissible jealousy; rather, it is an embellishment from Satan. A believer remains at ease concerning his religion as long as he does not shed unlawful blood.