AlQuran.My

Allah will not call you to account for thoughtlessness in your oaths, but for the intention in your hearts; and He is Oft-forgiving, Most Forbearing.

For those who take an oath for abstention from their wives, a waiting for four months is ordained; if then they return, Allah is Oft-forgiving, Most Merciful.

But if their intention is firm for divorce, Allah heareth and knoweth all things.

Divorced women shall wait concerning themselves for three monthly periods. Nor is it lawful for them to hide what Allah Hath created in their wombs, if they have faith in Allah and the Last Day. And their husbands have the better right to take them back in that period, if they wish for reconciliation. And women shall have rights similar to the rights against them, according to what is equitable; but men have a degree (of advantage) over them. And Allah is Exalted in Power, Wise.

A divorce is only permissible twice: after that, the parties should either hold Together on equitable terms, or separate with kindness. It is not lawful for you, (Men), to take back any of your gifts (from your wives), except when both parties fear that they would be unable to keep the limits ordained by Allah. If ye (judges) do indeed fear that they would be unable to keep the limits ordained by Allah, there is no blame on either of them if she give something for her freedom. These are the limits ordained by Allah. so do not transgress them if any do transgress the limits ordained by Allah, such persons wrong (Themselves as well as others).

So if a husband divorces his wife (irrevocably), He cannot, after that, re-marry her until after she has married another husband and He has divorced her. In that case there is no blame on either of them if they re-unite, provided they feel that they can keep the limits ordained by Allah. Such are the limits ordained by Allah, which He makes plain to those who understand.