The Cow - 2:229
Divorce is twice. Divorced women should either be kept in kindness or left in kindness. It is not lawful for you to take back what you have given them, except if the spouses fear that they may not observe the limits of Allah. If you fear that you may not observe the limits of Allah, then they will not be guilty of sin for what she has willingly given back. These are the limits of Allah; do not transgress them. Whoever transgresses the limits of Allah, they are the wrongdoers.
Divorce is twice. Divorced women should either be kept in kindness or left in kindness. It is not lawful for you to take back what you have given them, except if the spouses fear that they may not observe the limits of Allah. If you fear that you may not observe the limits of Allah, then they will not be guilty of sin for what she has willingly given back. These are the limits of Allah; do not transgress them. Whoever transgresses the limits of Allah, they are the wrongdoers.