Does a divorce occur through a threat of it, when the husband says to his wife: "If you mention this topic again, then you are divorced," if the wife later alludes to the topic rather than explicitly stating it? And does this condition remain in effect, or does it become void over time? And is the prayer of a husband addicted to unlawful things accepted?

Scholars have differed regarding the ruling on conditional divorce. Most of them hold the view that it takes effect upon the fulfillment of the condition, and this is the fatwa (definition) we follow. This is contrary to Ibn Taymiyyah, who considers it an expiation for an oath.

Accordingly, the divorce takes effect if the husband breaks his oath. However, the breaking of the oath depends on his intention at the time of uttering it, as intention specifies the general and restricts the absolute in an oath.

It is advisable to present the matter to the Sharia (definition) court or to reliable scholars. As for your husband, his committing of sins does not prevent his prayer from being accepted if he performs it correctly, but he must repent.