Does a divorce take effect with the statement, "Divorced be it, if you call your mother again, by God, you will remain divorced," if the husband did not intend for the divorce to occur?

Scholars differ regarding the ruling on swearing an oath by divorce and making it conditional. The majority of them hold that divorce occurs absolutely upon breaching the oath, and this is the fatwa we adhere to. Sheikh al-Islam Ibn Taymiyyah, however, is of the view that if swearing an oath by divorce is intended for emphasis, prevention, or encouragement, then an expiation for an oath (kaffarat yamin) is required upon breaching it, and divorce does not occur.

So, if you swore an oath and intended to absolutely prevent your wife from contacting her mother, then if she contacts her, divorce occurs. If you intended to prevent her from contacting her mother during a problem, then if she contacts her during that problem, divorce occurs. If divorce occurs and it is not yet the third divorce, you may take her back before her waiting period (iddah) expires. The permissible oath is by Allah Almighty, whereas swearing an oath by divorce is among the oaths of the dissolute.