The Ruling on Swearing by What Is Forbidden and by Divorce

Question:
What about the one who swears by what is forbidden and by divorce?

Answer:
This is not permissible; one does not swear by what is forbidden or by divorce.
And if he says, "I swear by what is forbidden," this is not permissible, because he has no right to declare forbidden what Allah has made lawful.
As for if he says, "I swear by divorce," this is not called an oath from the perspective of the Shari'ah; it is an oath from the perspective of language, from the perspective of the jurists' custom.
As for the oath, it is made with the letters b, t, w, h, and alif. As for "I swear by divorce," it is called an oath in the custom of the jurists because it contains emphasis.
Q: Does he divorce his wife?
The Shaykh: No, it is conditional according to his intention. On the correct view, if he intended to urge or prevent, it is an oath with the ruling of an oath. If he intended to effect the divorce, it takes place.