Does the divorce oath "If you contact this person directly or indirectly through another person, you will be divorced" take effect if the wife did not understand the phrase "indirectly through another person" and did so, and what is its expiation?

The majority of scholars hold that a conditional divorce takes effect upon the fulfillment of the condition, regardless of whether the intention was to effect the divorce or to threaten. This is the prevailing opinion (fatwa). So, if the wife contacts the man in question, her divorce takes effect. The husband may take her back as long as her waiting period (iddah) has not expired and the divorce has not become irreversible (three divorces).

Some scholars, like Ibn Taymiyyah, are of the view that the divorce does not take effect if there was no intention to effect it, and instead, an expiation (kaffarah) becomes due. They also differed on whether divorce takes effect if the wife performs the action sworn upon out of ignorance or misinterpretation. Most of them hold that it takes effect, while some hold that it does not, like Ibn Taymiyyah, who believes that divorce does not take effect in cases of forgetfulness, misinterpretation, removal of the cause, or error in the description.

It must be noted that a wife contacting a non-mahram man is a clear, apparent evil that should not be overlooked.