What is the ruling on a man marrying the woman with whom he committed zina after both of them have repented?

Question:
A man committed zina with a woman, and they all repented and he married her. Is there anything required of them?

Answer:
If they all repent with a valid repentance and then he contracts a valid marriage with her after the repentance, there is nothing wrong with that. However, he must not contract the marriage with her until the waiting period ('iddah) has passed from him, because she may have committed zina with someone else as well. Not contracting the marriage immediately is a requirement of the repentance, and the waiting period is necessary to ensure that she is not pregnant from having committed zina with another man while she was pregnant. Therefore, the repentance is required, and the second requirement is the completion of the waiting period.