What is incumbent upon a husband to do after discovering that his wife had been anally penetrated before marriage; should he continue in his marriage or separate?

If the act occurred during her childhood or without her consent, she bears no sin. However, if she was an adult acting by choice, she has committed a grave sin that necessitates sincere repentance and remorse. In this case, she should not be divorced; rather, she must be shielded and nurtured, for Allah accepts the repentance of His servants and transforms their evil deeds into good ones, as stated in Surat Al-Furqan: "Except for those who repent, believe and do righteous deeds. For them Allah will change their evil deeds into good ones. And Allah is Oft-Forgiving, Most Merciful."