What is the ruling on the covenant and oath sworn on the Quran between a man and a married woman who covenanted to marry after her divorce from her wicked husband, then the husband refused to officially divorce her?

The relationship between a man and an unmarriageable woman is reprehensible and forbidden. If the woman is married, the matter is even more strictly forbidden. What the questioner did by promising that woman marriage and inciting her to divorce her husband is a major sin, for the Messenger of Allah, peace and blessings be upon him, said: "He is not one of us who incites a woman against her husband or a slave against his master."

It is incumbent upon the questioner to repent to Allah by refraining from the sin, regretting it, and resolving not to return to it, along with concealing the sin and not publicizing it, and increasing in righteous deeds.

As for the oath not to leave that woman, it is an oath to commit a sin, and he must offer expiation for it: feeding ten poor people or clothing them. If he cannot find them, then fasting for three days.