What is the ruling regarding a husband's affirmation to his wife that a divorce has occurred, and does his failure to consult a mufti from the beginning necessitate the occurrence of divorce, especially after he said to his wife: "By Allah, I will divorce you if you do not do a certain thing," and she did not do it?

A divorce that is contingent upon a promise (such as "I will divorce you") does not take effect merely by uttering the oath. An oath made by Allah is based on the intention of the swearer. If you intended immediate divorce and your wife did not do what you intended, then you may divorce her, and there is no expiation upon you, or you may expiate for your oath and refrain from divorcing her, which is preferable. However, if you did not intend immediacy, then you do not break your oath unless the wife's action becomes impossible. Your delay in seeking a fatwa does not result in divorce, and you are not sinful due to ignorance in this matter.