The ruling on one who kills without the intention to kill

This is a letter that reached us from the questioner Muhammad Ibrahim Ismail, residing in Tathlith, of Egyptian nationality. He says: I have a cousin whose father passed away, so my father took him in and raised him. However, a discussion arose between us on a topic, and the discussion between us escalated. I had a knife in my pocket, and without realizing it, I struck him with it. He died immediately afterward, but I did not intend to kill him, and there was no prior enmity between us, because we live in the same house. My father testified to this before the judge, so he sentenced me to seven years in prison. But I feel that this is not enough, for I have repented to Allah and I want the Islamic ruling on this matter; because I am in the greatest anxiety due to my fear of Allah (Glorified and Exalted is He), so guide us to the good, may Allah reward you?
Answer: This issue concerns the judiciary and courts. If the guardians of the deceased forgive you and drop their right, there is no harm. And you must repent to Allah for what came from you. As for if they demand their right of retaliation or blood money, that is for the courts. The Sharia court looks into that and into what the court deems appropriate in light of the Sharia evidence, the blessing and sufficiency. And if you know that you were deliberate and that you intended to kill him, then present yourself, present yourself, and it does not need the court. Say to them: I wronged myself, and I made a mistake, and I am the one who committed the evil, and I intended to kill him. If they forgive you, there is no harm. And if they kill you, they have the right to kill you in retaliation, and they are the guardians of the blood and the heirs of the slain. But if you claim that this happened from you without intention, that the knife slipped from you, or that you stabbed him with the knife while you were not conscious, this is a matter that returns to the judiciary. The judge looks into it, and after looking into it, it will become clear to him, if Allah wills, what is obligatory upon you. Allah is the Helper. Yes.
The presenter: May Allah reward you.