Commentary on Tafsir al-Jalalayn: (( He said )) to him in mockery (( By Allah, if )) it is the light form of the heavy form (( you nearly )) you came close (( to cast me down )) to destroy me

And for this reason, he said to him The author said he said it to him in mockery; this is what the author held, that he said it to him mocking him. It is also possible that he said it while speaking of Allah’s favor, This is the most likely interpretation. He said to him, "By Allah, if" is the light form of the heavy form.
His saying This is an oath using the letter taa. An oath is a definition of emphasizing a thing by mentioning something esteemed in a specific form. The oath was for emphasis because the one taking the oath is as if saying in his heart, "The status of this in my view and its value in my view, I use it to confirm what I have reported, if it is a report, or what I will do, if it is a declaration. In any case, an oath is emphasizing a thing by mentioning something esteemed in a specific form. There are three letters of oath: waw, taa, and ba. They differ; the most commonly used is waw, and the most comprehensive in usage is ba, because ba is used for oaths with an explicit name, such as "I swear by Allah," and with a pronoun, such as "By the Lord, I swear by Him that I will certainly do such and such," both with the mention of the operative verb and with its omission. As for waw, it does not enter except on an explicit name, and the operative verb must be omitted with it. As for taa, it does not enter except on specific names, namely Allah and Rabb (Lord), and it is said that it also enters on al-Rahman (the Most Merciful). However, the operative verb of the oath is not mentioned with it. So the most comprehensive in usage is ba, and the most commonly used is waw.
He said "If you nearly." The author says that "in" is the light form of the heavy form. So its original form is "inna," and thus it conveys emphasis. The reason it is called the light form of the heavy form is that "in" comes in multiple forms, which Muhammad al-Shahri will explain.
The student: It comes as the light form of the heavy form.
The Shaykh : It comes as the light form of the heavy form.
The student: ...

The Shaykh : No, if it becomes not the light form, it becomes "inna." We are discussing "in" coming as the light form of the heavy form.
The student: And it comes as a negator.

The Shaykh : And it comes as a negator.
The student: And it comes as a conditional.
The Shaykh : And it comes as a conditional.
The student: And it comes as superfluous.

The Shaykh : And it comes as superfluous. An example of the conditional, Muhammad?
The student: If I were to do it.

The Shaykh : If I were to do it.
The student: If Zayd stands up, I will give him money.

The Shaykh : If Zayd stands up, I will give him money. This is a conditional negator, Khalid?
The student:
The Shaykh : Superfluous. Yes, that is correct, 'Adil?
The student: Banu Ghadana, and so on.

The Shaykh : And so on. The evidence is his saying "Not that you are gone" because the estimation is "You are not gone." This is used in the sense of "ma" of the Hijaz, which functions like "laysa" on the condition that "in" superfluous does not follow it. Good.
He said "If you nearly to cast me down" "You nearly." The author says "You came close" because "kadda" (nearly) indicates proximity, so it is one of the verbs of proximity. It has become well-known among grammarians that its negation is affirmation and its affirmation is negation. So if you say "He nearly did it," this is affirmation, but it indicates that he did not do it. Otherwise, did he do it? He did not do it. And if you say "He did not nearly do such and such," this is negation, but it indicates that he did do it, due to the saying of the Exalted, But this well-known view is not correct. So "kadda" is like other verbs: its affirmation is affirmation and its negation is negation. If you say "He nearly did such and such," if it means "came close," it indicates by its root that he did not do it, because one who comes close to a thing does not enter into it. And on this basis, its affirmation is affirmation; it affirmed the proximity, and the proximity indicates the non-occurrence of the action. As for "He did not nearly do such and such," this also indicates the non-occurrence of the action and that he did not come close to doing that thing. But if there is a context indicating the action, such as the Exalted saying The affirmation came from the word "so they slaughtered it," not from the word "they did not nearly do it." For this reason, Allah, Glorified and Exalted, said [An-Nur: 40]. Do we say that he sees it? No, rather we say it is not said that he sees it, because this great darkness is beside your eye; you cannot see. So this well-known view is not correct. Rather, we say that "kadda" is like other verbs: its affirmation is affirmation and its negation is negation, but its meaning is the meaning of proximity. Good.
He said The lām is for emphasis. But some grammarians refer to it by saying "the lām of distinction" or "the lām of differentiation." They mean by this that it distinguishes between the negating "in" and the "in" that is the light form of the heavy form. Because if it comes after "in," it indicates that it is the light form of the heavy form and not a negator, because negation is not emphasized with the lām. Is this lām of distinction obligatory in the predicate of "in"? We say there is a detail in this: if the meaning is clear, it is not obligatory. If the meaning is obscure, it is obligatory. That is to say, if the context allows for "in" to be for negation, it is obligatory to bring the lām of distinction. If it does not allow for that, it is not obligatory. So the saying of the poet:
"And if Malik were the noble of minerals"
The lām did not come in this because the context intends to praise these tribes, and praise is not suitable for negation; rather, it is suitable for affirmation. But if you say "Inna Zaydan qayyaman" (If Zayd is standing), it is obligatory for you to bring the lām, so you say "Inna Zaydan laqayyaman" (Indeed Zayd is standing). Why? Because if you did not bring the lām, it would be possible that the meaning of your saying "Inna Zaydan qayyaman" is "Zayd is not standing." For this reason, some grammarians called it the lām of distinction or the lām of differentiation. For this reason, Ibn Malik said:
"And you lightened 'in' so its work was little, and the lām is obligatory if it is neglected
And perhaps it is dispensed with if what the speaker intended is clear and relied upon"
So he, may Allah have mercy on him, clarified that the lām is obligatory if it is neglected. As for if it is made operative, the matter is clear. We say "Inna Zaydan qayyaman" (If Zayd is standing), so there is no need for the lām. Why? Because the negating "in" does not put the subject in the accusative and raise the predicate. And what puts the subject in the accusative and raises the predicate is "in" the light form of the heavy form. The summary of this grammatical issue is that we say "in" the light form of the heavy form operates, but its operation is little. If it is neglected, the lām is obligatory in its predicate, unless the meaning is clear. If you say "Inna Zaydan qayyaman" (If Zayd is standing), the lām is obligatory. Otherwise? Because the negating "in" does not put the subject in the accusative, so the meaning is clear that it is the light form. And if you say "Inna Zaydan qayyaman" (If Zayd is standing), it is obligatory to bring the lām, because if you omitted it, it would be possible that it is for negation and that it is for affirmation. Good. And if a man is praising a person and says "Inna Zaydan kariman" (If Zayd is noble):
The student: ...
The Shaykh : Because negation requires that "in" be the light form of the heavy form, not a negator. And Allah knows best.