What is the ruling on making a vow regarding a permissible matter? And what is the ruling on fulfilling it?

The questioner : There are questions about vows: Is the form of making a condition in a vow permissible? For example, saying: "If so-and-so returns from his trip, I will send a sheep to his house," without there being any obedience in this vow. What does it mean? What is the worship or obedience to Allah in sending a sheep to so-and-so for him to eat?

The Shaykh : Here is a matter that requires detailing the speech, even if briefly. A vow is of two types: a vow of obedience and a vow of disobedience.
A vow of obedience: It is obligatory to fulfill it.
A vow of disobedience: It is not permissible to fulfill it.
A vow of obedience is of two types:
The first: A vow of seeking reward and drawing near to Allah (Blessed and Exalted is He).
The other: A vow that we might call today a "barter," and which they used to call in the past a "vow of exchange."
The first type: A vow of seeking reward means drawing near to Allah (Mighty and Majestic). It is the one who says this to compel himself to draw near to Allah (Mighty and Majestic) through obedience, because he feels that he is lazy and that if he is not bound by a vow, he may not be able to perform that worship. So he says, for example: "It is obligatory upon me for the sake of Allah to pray two rak'ahs between Dhuhr and Asr every day." This is a vow of seeking reward and obedience, and it is obligatory to fulfill it.
As for the vow of barter or the vow of exchange: This is what the question was about. It is when a person says: "If so-and-so comes, it is obligatory upon me for the sake of Allah to do such-and-such," or "If Allah grants me a boy, it is obligatory upon me for the sake of Allah to do such-and-such." This is a vow of exchange or barter, as if he is saying with his state: "O Lord, if You are in accordance with my desire and You spare my child, I will slaughter a ram for You; and if You are not in accordance with my desire, I will not slaughter anything for You." This is undoubtedly not prescribed in Islam. In fact, an explicit text has come forbidding it, in His saying (peace and blessings be upon him): . So this one who has bartered with Allah and exchanged benefit with Him, saying "If You spare my child, I owe You such-and-such; if You do not spare him, I owe You nothing," this is the miserly, stingy person. But if he is generous in spirit, he offers charity before his sick child, as came in the good hadith by the sum of its chains: . So if the vow is a vow of barter, it is not prescribed to make it. But if he makes it, he must fulfill it, because it is a vow of obedience. We are now speaking about the first type. We said a vow is of two types: obedience and disobedience. A vow of disobedience is not permissible to fulfill, and a vow of obedience is of two types: a type that is a vow of seeking reward and obedience and increasing nearness to Allah; this obligates fulfilling it, and it is prescribed to make and vow it. As for the second vow, which is the vow of exchange or barter, it is not prescribed to make it. But if one makes it, it is obligatory to fulfill it, because it is a vow of obedience.
As for if it is—and this applies to every case in any matter that is not described as disobedience—the question that came is undoubtedly either a vow of obedience or a vow of disobedience. But it falls under the second type of vow of obedience, which is the vow of exchange or barter. So it is obligatory to fulfill it, and it is not good to make it.