Continuation of the explanation of the author's statement: And his saying: . . . . . For there is no fulfillment of a vow in disobedience to Allah.

The Shaykh : He (peace and blessings be upon him) gave the reason, saying: .
No: This is a negation of the genus. Is it "la" or not? And "wafa'" (fulfillment): Yes, that is its subject, and "li-nadhr" (for a vow) is its predicate. And is a description of the vow, meaning that it is not possible to fulfill a vow in disobedience to Allah, because one does not draw near to Allah through His disobedience, and disobedience is not permissible so that we would say: do it.
And the vow is divided into two parts, or rather three parts, and some say five, but let us look at it now:
First: that which must be fulfilled, and second: that which is forbidden to fulfill, and third: that which follows the course of an oath, meaning if he wishes he fulfills it, and if he wishes he expiates. So the vow is three parts:
That which must be fulfilled, that which is forbidden to fulfill, and that which follows the course of an oath.
What is that which must be fulfilled? A vow of obedience, based on the saying of the Prophet (peace and blessings be upon him): .
And that which is forbidden to fulfill is a vow of disobedience, based on his saying (peace and blessings be upon him): And here he said: .
And that which follows the course of an oath is the permissible vow and the vow of contention and anger... It is not necessary that it be contention and anger; it is the permissible vow. What is an example of a permissible vow? For example, he says: "I have a vow upon me to Allah to wear this garment." What is this? This is a permissible vow. Wearing this specific garment, if he wishes he wears it, and if he wishes he does not wear it. So its ruling is the ruling of an oath: if he wishes he wears the garment, and if he wishes he does not wear it and expiates with the expiation of an oath.
The vow of contention also follows the course of an oath, and it is that which intends the meaning of an oath, meaning that he intends to urge or prevent, or to verify, or to deny... That what was done, he is given the choice between doing it and the expiation of an oath. Its example: So-and-so said: "Today such and such happened," and the other said: "It did not happen. If this is true, I have a vow upon me to Allah to fast for a year, or to fast for a month." Yes, what is the purpose of this vow? The purpose is denial. He says: "You are lying. If this is true, I have a vow upon me to Allah to fast for a month." So here it becomes clear that he is truthful, it becomes clear that the reporter is truthful. Did the vow-maker break his vow or not? He broke it. He is now given the choice between fasting for a year or expiating with the expiation of an oath, because if he fasts for a month, he has fulfilled his vow and has not broken it, and if he does not fast, he has broken it, and the one who breaks an oath expiates with the expiation of an oath. Similarly, if a guest comes to a person and he wants to slaughter a sacrificial animal for the guest and says: "If I slaughter this sacrificial animal, I have a vow upon me to Allah that I will fast for two months." He says to the host: "What is his purpose?" So that he will refrain, because he is not going to slaughter it, so that he will fast for two months. But the host slaughtered it. So what happens? We say to this vow-maker: If you wish, fast for two months, and if you wish, expiate with the expiation of an oath.
The student: The evidence that he expiates with the expiation of an oath.

The Shaykh : Because Allah says: So Allah made prohibition an oath. And a vow is making something obligatory, but it is the opposite of prohibition.