Remarriage
When you divorce women, do not prevent them from remarrying their former husbands if they mutually agree in fairness. This is a command for those who believe in Allah and the Last Day; it is purer and more righteous for you. Allah knows, while you do not know.
2:232And when ye have divorced women and they reach their term, place not difficulties in the way of their marrying their husbands if it is agreed between them in kindness. This is an admonition for him among you who believeth in Allah and the Last Day. That is more virtuous for you, and cleaner. Allah knoweth; ye know not.