What is the ruling regarding someone who said to his wife, "I divorce you, I will not book for you now, even if you want to come to me," intending by the divorce to challenge, threaten, and provoke, and he is now in need of her coming to him?

If you reserve divorce for your wife before the examination, she will be divorced from you according to the majority of scholars. If you have not divorced her more than once before, you may take her back during her 'iddah (waiting period). Some scholars, like Ibn Taymiyyah, hold the view that the divorce does not occur if your intention was to threaten, not to effect divorce, and in this case, you must offer an expiation for breaking an oath.