Al-Baqara — Ruku 29

Divorce is twice. Then, either keep [her] in an acceptable manner or release [her] with good treatment. And it is not lawful for you to take anything of what you have given them unless both fear that they will not be able to keep [within] the limits of Allah. But if you fear that they will not keep [within] the limits of Allah, then there is no blame upon either of them concerning that by which she ransoms herself. These are the limits of Allah, so do not transgress them. And whoever transgresses the limits of Allah - it is those who are the wrongdoers.

And if he has divorced her [for the third time], then she is not lawful to him afterward until [after] she marries a husband other than him. And if the latter husband divorces her [or dies], there is no blame upon the woman and her former husband for returning to each other if they think that they can keep [within] the limits of Allah. These are the limits of Allah, which He makes clear to a people who know.

And when you divorce women and they have [nearly] fulfilled their term, either retain them according to acceptable terms or release them according to acceptable terms, and do not keep them, intending harm, to transgress [against them]. And whoever does that has certainly wronged himself. And do not take the verses of Allah in jest. And remember the favor of Allah upon you and what has been revealed to you of the Book and wisdom by which He instructs you. And fear Allah and know that Allah is Knowing of all things.