What is the ruling of Islamic law regarding a man divorcing his extremely religious wife, after years of marriage and having children, because the husband remembered that the wife had bad behavior (dancing at mixed-gender weddings and kissing her cousin's son) before their engagement?

A husband must hold onto his wife and live with her honorably as long as she remains chaste and shows no suspicious behavior. He must also beware of the whispers of Satan. It is neither wise nor just to dwell on the wife's past from which she has repented, for repentance erases what came before it. The consideration is the woman's current state, not her past, and it is wrong to inquire about the past and seek out missteps.