Chapter: "Chapter on the one who says to his brother, 'O disbeliever'" Explanation of the hadith of Ibn 'Umar (may Allah be pleased with both of them), who said

The Shaykh : The author (may Allah have mercy on him) said in the chapter after the two hundred and fifth.
"Chapter on the one who says to his brother, 'O disbeliever'".
The hadith he cited in this chapter had previously been mentioned with a different wording. It seems he is now drawing attention to another meaning that aligns with the previous one, as he is narrating it here with a sound chain of transmission.
From Ibn 'Umar that the Messenger of Allah (peace and blessings be upon him) said: .
This hadith appeared in a previous chapter with the wording: .
In terms of meaning, this hadith confirms the meaning of the previous hadith. It says, "Whoever says to his brother, 'O disbeliever,' meaning 'you are a disbeliever' or 'he is a disbeliever'—this is the estimated meaning—then one of the two has returned to it." We have already learned the correct meaning of such a phrase from the previous lesson. "One of the two has returned to it" means: if the person addressed is truly a disbeliever, then the word has fallen in its proper place. If the person addressed is not a disbeliever, but rather a Muslim, though he may be an open sinner or even a righteous person, then the name of disbeliever returns to the one who applied the word "disbeliever" to that Muslim.
I want to emphasize what I explained in the previous lesson. The hadith gives us two things:
The first thing is that it is not permissible for a Muslim to declare another Muslim a disbeliever, and this is clear. The second thing, and here lies the precision: if a Muslim says to his Muslim brother, "You are a disbeliever," and the one declared a disbeliever—the one to whom it was said—is a Muslim in appearance, but in reality, Allah knows that he is a disbeliever, then the word has fallen in its proper place, and there is no sin on the one who uttered the word of disbelief. This is also clear. But the precision lies in the case where the matter is not so; that is, if the one declared a disbeliever is not a disbeliever in the knowledge of Allah the Exalted and does not deserve the word "disbeliever," then what befalls the one who declared him a disbeliever? The apparent meaning of the hadith is that it returns to him; he becomes a disbeliever. If he does not become a disbeliever, then what is the meaning? The sin of disbelief befalls him. The sin of disbelief. Zayd said to 'Amr, "You are a disbeliever." 'Amr, the one declared a disbeliever, is in one of two states: either he is truly a disbeliever in the knowledge of Allah, in which case the word hit its mark and there is no sin on the one who declared him a disbeliever. Or, if the reality is that the one declared a disbeliever, who is 'Amr, is not a disbeliever in the reality of the knowledge of Allah the Exalted, but is a Muslim, then the sin of declaring someone a disbeliever returns to the one who declared him. The sin of declaring someone a disbeliever returns to him; the ruling of disbelief does not return to him. Do you understand? The issue is this: may Allah forbid, if I say to one of the Muslims, "You are a disbeliever," and if this person appears to us to be a Muslim, but I have ascertained the reality of his matter and said to him, "You are a disbeliever," and indeed he is a disbeliever in the knowledge of Allah, then there is nothing wrong; the word hit its mark. But may Allah forbid, if he is a Muslim in the knowledge of Allah the Exalted, and I either intentionally sought to harm him and slander him without right, or I made a mistake, then in that case, that word does not touch him with harm; he remains a Muslim as Allah the Exalted knows him. But I, by saying to him "disbeliever" when he is not a disbeliever—the hadith says . We said he is a Muslim, not a disbeliever. So, do I return to this declaration of disbelief?
The answer is: I return, may Allah forbid, to the sin of declaring someone a disbeliever, not to the ruling of disbelief. I have clarified this issue to you because it is very important, as many people understand that as soon as one person says to another, "O disbeliever," or as passed in the previous hadith, "O enemy of Allah," that it returns to him and he becomes what? A disbeliever merely by the word his Muslim brother accused him with, or merely by saying to him "O enemy of Allah," he becomes an enemy of Allah. No. If that person is a Muslim and not a disbeliever, and not an enemy of Allah, then the sin of declaring someone a disbeliever befalls the one labeled with this word, not the ruling of disbelief. So the author seems to have repeated this chapter to focus this reality in the mind of the Muslim.
With the same meaning, the second hadith in this chapter, which is also from Ibn 'Umar, but with the wording . Memorize this: instead of "with disbelief," it is "with the sin of disbelief" or "with the sin of declaring someone a disbeliever." This is more correct.