Is it permissible to marry a woman with whom adultery was committed once before the completion of the marriage contract, knowing that both parties are remorseful and wish to marry lawfully?

Adultery is a grave sin. Its expiation is sincere repentance, which involves regretting the act, seeking forgiveness, resolving not to return to it, and increasing good deeds. If the two adulterers repent, there is no impediment to their marriage, provided that the woman repents and observes the iddah (definition) (waiting period) from the adultery: by giving birth if she is pregnant, or by one menstrual cycle if she is not pregnant.