Does divorce take effect in the following situations: uttering it to oneself and threatening oneself with it, or during an argument with the wife, or upon declaring her forbidden until the Day of Judgment?

The madhhab of the majority of scholars is that if one swears an oath of divorce and then breaks it, the divorce takes effect. If you uttered the oath of divorce the first time and then broke it, the divorce has taken place. However, if it was merely an inner thought, then nothing is binding upon you. Your saying to her, "You are divorced," is an immediate divorce. And your saying, "Divorce be upon me, you are not binding upon me," if you intended by it that she should not remain your wife and you then broke the oath, then the divorce has also taken place. With this, your wife has become irrevocably divorced from you (baynunah kubra), so she is not lawful for you until she marries another husband. Repeated oaths by the majestic name of Allah in a single sitting for emphasis require one expiation according to the most preponderant opinion; otherwise, each oath requires an expiation. And a man's saying to his wife, "By Allah, I do not want her," is a kinayah (allusion) of divorce. If he intended divorce by it, it takes effect; otherwise, it does not. As for your saying, "She is forbidden to me," refer to Fatwa No. 33642, where we explained the ruling on a man making his wife forbidden to himself and that it depends on his intention.