Answer: As regards this matter, you state that you both pronounced divorce and made a declaration of ẓihār toward your wife so that she would not speak to her sister. If your only aim in doing so was to stop your wife from talking to her sister, and you did not actually intend for the divorce to take effect, nor did you intend to make a binding ẓihār, then what is incumbent upon you—according to the sounder of the two scholarly opinions—is the expiation for breaking an oath. Once you have paid that expiation, these oaths are dissolved. Allah, the Exalted, knows best.
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Question: A quarrel broke out between my wife and me. I became violently angry, beat her severely, and swore an oath of divorce against her. My wife, however, refused to leave the house; everything soon returned to normal and our marital life continued. She later gave birth to three children, and until this moment no one but Allah ﷻ knows what took place between us. What must I do now?

Answer: First, the anger you felt toward your wife and the severe beating you gave her are blameworthy and impermissible. When anger overtakes you, you must seek refuge with Allah from Satan the accursed, and you must not strike your wife or abuse her to such an extent.

As for the oath of divorce you made, you have not specified the exact wording you used. If what you meant by swearing divorce was simply to stop her from doing something, or to compel her to do something, then—according to the sounder of the two scholarly opinions—such a formula carries the ruling of an oath, and you must therefore pay the expiation for breaking an oath. If, however, your intention in swearing was to enact an immediate, effective divorce prompted by your anger and the beating—and that anger did not make you lose full awareness—then the divorce has taken effect. If it was fewer than three pronouncements and you later resumed marital relations, that resumption counts as a valid revocation.