And those who pronounce ẓihār from their wives and then [wish to] go back on what they said - then [there must be] the freeing of a slave before they touch one another. That is what you are admonished thereby; and Allāh is Aware of what you do.
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.