The ruling on one who made a vow of obedience contingent on the occurrence of something that did not occur

Question:
From Sana'a, a message was sent by one of the listeners. She says: The sender is Umm Marwan, Abdullah Nasr, Umm Marwan. She has a collection of questions, one of which says: I have a neighbor who has not become pregnant, and she vowed to Allah to slaughter a sheep and give it to the poor if she became pregnant. But two years have now passed and she has not become pregnant. What is obligatory upon her?

Answer:
When she becomes pregnant, she must fulfill her vow. The Prophet (peace and blessings be upon him) said: narrated by al-Bukhari in the Sahih. So if Allah makes pregnancy easy for her, He will make her affairs easy; let her slaughter a good sheep like the 'Id sacrifice, a one-year-old sheep or a two-year-old goat, slaughtered free from defects for the poor. It should be a good sacrifice, without defects, not sick, not with a broken horn, not with a cut ear, free from defects, like the 'Id sacrifice. She slaughters it and distributes it to the poor if Allah makes her pregnancy easy.
If Allah makes her pregnancy easy, she must fulfill the vow. As long as she has not become pregnant, she owes nothing, and praise be to Allah. We advise her not to make vows. We advise every Muslim not to make vows; because of the saying of the Prophet (peace and blessings be upon him): recorded by the two Shaykhs in the two Sahihs.
So a vow does not bring good. We advise everyone not to make vows; because of his saying (peace and blessings be upon him): But whoever vows to obey Allah, he must obey Allah; because of the saying of Allah, the Exalted: [Al-Insan:7] So the believers fulfill their vows of obedience. As for a vow of disobedience, it is not fulfilled. If he said: It is upon me for Allah that I commit zina, it is not permissible for him to commit zina. He owes the expiation for an oath. Or if he said: It is upon me for Allah that I strike so-and-so without right, it is not permissible for him, and he owes the expiation for an oath for his vow, a vow of disobedience. Or if he said: It is upon me for Allah that I steal, it is not permissible for him, and he must repent to Allah and pay the expiation for an oath.
As for a permissible thing, if he said: I vowed to Allah that I will visit so-and-so, or eat so-and-so's food, or speak to so-and-so, he has a choice. If he wishes, he does it, and if he wishes, he pays the expiation for his oath. And if he visits his brother, because visiting is recommended, if his brother is a good man, visiting is more appropriate, as it is a type of worship.
So it is better to fulfill his vow and visit his brother. If he is a good brother whose visit is good, it is better to visit him, and it is safer to visit him and not pay the expiation. .... obedience, and the Messenger (peace and blessings be upon him) says: .
As for if he said: It is upon me for Allah that I eat such-and-such, or drink such-and-such, or do such-and-such of the permissible things; he has a choice. If he wishes, he does it, and if he wishes, he pays the expiation for his oath. Yes.

The presenter : May Allah reward you with good, and may He do you good.