Is the marriage still valid, or must it be renewed after the husband denied it then later affirmed it?

The question cannot be answered without knowing the exact words uttered by the husband and his intention. If, by his denial, he intended to conceal the marriage without intending divorce, then no divorce occurs. The jurists mentioned that if a man is asked, "Do you have a wife?" and he replies, "No," while he is lying, no divorce occurs because it is an allusive expression (kinayah) that requires the intention of divorce. If the husband says, "So-and-so is not my wife," and he intends divorce, then it occurs; otherwise, it does not. However, if he denies the marriage by saying, "I did not marry So-and-so," this is a lie by which no divorce occurs.