Al-Mujadila · 58:3

3. It is necessary upon those who utter this disgusting statement and then intend to have sexual intercourse with the wife they did Ẓihār to, that they make amends by freeing a slave before they have intercourse. This aforementioned ruling you have been commanded to carry out is a reprimand for you for the Ẓihār. And Allah is aware of your actions; none of your actions are hidden from Him.