How is the prophet sure that it is God Himself speaking to him?

See briefly here about your question:
https://mikyab.net/%D7%A9%D7%95%D7%AA/%D7%94%D7%90%D7%9D-%D7%94%D7%9E%D7%95%D7%A1%D7%A8-%D7%94%D7%95%D7%90-%D7%94%D7%95%D7%90-%D7%94%D7%94%D7%AA%D7%92%D7%9C%D7%95%D7%AA

I think my question does not come from a place of skepticism, it is about the problem of definition and identity between the biblical ’ and the experience that the prophet experienced.
That is, the problem here is more than just internal conviction. The prophet did not learn in kindergarten what the ’ looks like and how it sounds. The teacher did not point to him and say, ” Look, ’ This is the ’ and this is not the “. That is, on the surface, it seems that the prophet defines this experience as ’ on his own. It is possible that if another person experienced the exact same experience, he would define it as just a daydream or hallucination.

Is it possible that the prophets did not experience a revelation, and only used this phenomenon that was so common at the time to convey their message?

Anything is possible, but the Torah itself speaks of prophecy and the revelation of God to them. Therefore, whoever claims otherwise will be left with the evidence.
In the link provided above, I commented on the prophet's self-certainty. The fact that he has never experienced something does not mean that he cannot perceive it. On the contrary, the doubt about his experience stems from the fact that you have never experienced such a thing and therefore are not touched by the certainty that accompanies it. Like a blind person wondering about the reliability of the sense of sight.
And even more so, previous experiences cannot solve the problem because they also began with the first experience, and if it cannot be believed, then so can the second one, and so on. Experience does not solve the problem you raise, if there is one.

When a blind man opens his eyes, someone will have to point to him and tell him, “This is red and this is green.” It is a matter of definition. So when someone experiences an experience where they hear a voice or something else, it is not possible for them to decide on their own that it is the same experience that Moses experienced.
If we believe that the prophets were honest men, it is better to say that they did not have any hallucinatory revelation. Rather, they used God to convey a message.

Why can't God tell them that this is a prophecy? What is the meaning of this insistence? I wonder!!

Here is a Hasidic wort from Rabbi Mendel of Rimonov (Torat Shimon Per Veir, Devas HaSadeh, 3).

The wort deals with exactly the above topic – How did Abraham know that the revelation to him was from God Himself? The question is explained well, but the answer is not clear to me. I would be happy if you could give your opinion.

“And Abraham said to his young men, “Sit here with the donkey, and I and the young man will go over here and bow down and come back to you”.
It is known from all the holy books how great the motives he had for the אגעה at the time of the Akedah – In short, he had all the motivations that could be in the world, because it is not for nothing that this experience stands with us from now on until the end of all generations, and thanks to it we are survivors of all kinds of calamities, and every year our sins are atoned for.

And surely the devil then made all kinds of tricks that were possible to do to prevent him from the commandments of the Lord and our father Abraham, with the great warmth of the ardent fire burning within him, a great and terrible fire to fulfill the will of his Maker, the Creator, did not look at all this and overcame everything and went with great joy to offer up his only son as a burnt offering.

And when the devil saw that after all his effort and trouble he had not succeeded, he tried one more test, perhaps he would catch him in this matter to overthrow God, and he appeared to him as a righteous and righteous man walking towards him and giving him peace in the way of love, properly and correctly, and asked him: Where is he going? And he would reply: I am going to do the will of my Creator, who commanded me to slaughter my only son. And he would reply to him: Blessed are you, Abraham, that you are going to do the will of your Creator in particular in such a great matter. Go in peace. But please tell me, my friend, how do you know that it is indeed the will of the Holy One to slaughter your son? And Abraham would reply to him, "Yes, God: I myself heard from the mouth of the Holy One, take your son, and so on."

Then the aforementioned man said to him: Blessed are you, you have certainly been granted a great word, and not every person is granted to hear words from the mouth of the Holy One Himself. With all this, I will not hesitate to reveal to you what I have heard and received from my masters, that not every person is granted to hear words from the mouth of the Holy One Himself, and even if he does hear, he should not rely on it at all, because perhaps he is from some other side. Only he who knows for himself that he has already corrected all his sins, especially the sins of his youth, and that there is no sin in him and is as strong as an angel, then he is certain that the glory of God spoke to him in truth, but whoever is still doubtful whether he has already corrected the sins of his youth in every way, then God forbid he should look at such speech as this, so you yourself should see where the speech came from.

And when Aa'ah heard this, he stood in great fear, for due to the greatness of his humility and lowliness, he feared his words, as was the way of the righteous, and this ruse almost brought down the greatness of the joy and enthusiasm that he had at that time, and he immediately strengthened himself and said: God forbid that anything in the world should dissuade me from my work, although the truth is that I have not yet corrected the sin of my youth.

And this is “And Abraham said to his young men” meaning he said to his young men “Sit here with the donkey” with his materialism, “And I and the young man” meaning I with the sons of Isaac “We will go over here and bow down and turn back to you [to you]” I promise you that I will come there to the great stage to bow in great humility and then I will return to you as well, and for now there is nothing in the world that will stop me, G-d, and I will go with great joy to fulfill the commandments of the house of worship.

After the Lord, we understand that God is transcendent, "Holy, Holy, Holy," and that there is something so immanent about His revelation to the Son that it is difficult for us to grasp this after the holiness of the day because it is terrible and awful.

There is no answer here of course. He simply left the motives with the boys and everything is great. Hasidic worts in the ghosh

I don't understand how we know that the prophet didn't exaggerate and ”cut corners”. He imagined/dreamed/invented and convinced everyone he’talked to. Who said that he himself was necessarily convinced of this? And the same goes for the status of Mount Sinai. How do we know that they were so convinced 100 percent and to a level where there is no room for error, like a wise man facing a blind man. Where exactly is it written? And maybe the wise man can also lie and claim that he sees a flying white horse playing the darbuka? After all, he sees and the blind man has to believe everything that comes out of his mouth… I'm not a skeptic either, which doesn't mean I'm obligated to believe everything I'm told.

You're really not obligated. We're done.

There is no reason for a normal person surrounded by crazy people that God is talking to (false prophets) to believe that the voice he hears is God Himself speaking to him and not to others. A reasonable person would tell himself that this voice he hears or this experience he has is just a hallucination.
Therefore, the only reasonable interpretation regarding the true prophets is that God did not speak to them, and they only used it because then they only listened to those that God is talking to.

And the reason for the insistence is, I do not remember God speaking to me or to anyone else that I know.

Did God speak to the Rabbi?

You know what? Maybe he's talking to me under Nick Zerubbel.

Today, metaphysical experiences such as clinical death can be tested, as the hormone expressed in death and birth, called ketamine. Moreover, today, transcendental experiences can even be had in laboratories by isolating certain hormones. When we are aware of the way we experience things, it is difficult not to wonder about the predictions of those same ones.
My point is that no matter how strong the intensity of the event, as long as it is individual, it is impossible to know whether it is a revelation or a hormonal dysregulation.

True. Today it is also possible to create visual illusions. According to the same logic, you should not believe in vision either. My assumption is that as long as there is no indication that it is an illusion, it is a matter of consciousness. Of course, each case is unique, and each person is different according to their feelings and circumstances.

Zerubbabel, this is the very power of mass testimony. How do we know that we are right and that the madman is the madman? How can it be that he is not right and we are all wrong?

It remains only to note that prophecy ceased at the exact same time as it ceased more or less for the other nations... [apart from exceptional individuals like Jesus and Muhammad. Once upon a time, every king had a gang of prophets and dream interpreters in his court].