either retain her or release her; the decision is yours. “It is not lawful for you to take back anything of what you have given them, unless both fear that they may not uphold the limits set by Allah. But if you fear that they may not uphold Allah’s limits, then there is no blame upon either of them concerning that by which she ransoms herself.” [al-Baqarah 2:229]
Thus, this separation is regarded as a ransom. Then Allah, exalted is He, says: “And if he divorces her, she is not lawful to him thereafter until she marries another husband.” [al-Baqarah 2:230] If we were to count khulʿ as a divorce, then His words, “And if he divorces her,” would refer to a fourth divorce, which is contrary to scholarly consensus. Therefore, His words, “And if he divorces her,” refer to the third divorce: “she is not lawful to him thereafter until she marries another husband.” The indication of the verse is clear. For this reason, Ibn Abbas, may Allah be pleased with him, held that every separation involving compensation is khulʿ and not divorce, even if it is effected with the explicit wording of divorce. This is the stronger view.
His statement, “an irrevocable divorce”: irrevocability means separation. Irrevocable divorce is of two types: a major irrevocable separation, which is the third divorce; and a minor irrevocable separation, which is divorce in return for compensation. Thus, if a man has previously divorced his wife twice and then divorces her a third time, we say: this divorce constitutes a major irrevocable separation, meaning that she is not lawful for him unless she first marries another husband. But if he divorces her in return for compensation, it constitutes a minor irrevocable separation.
What, then, does “irrevocable” mean? It means that he may not take her back in marriage; even if he were to do so, it would not be valid. The reason is that her payment of compensation is a ransom: she has bought her freedom. If we were to allow the husband to take her back, there would be no benefit in this ransom, and she would be no different from a woman who had paid no compensation. Thus, the woman who pays compensation is as though she has bought herself from her husband. Therefore, we say that it is an irrevocable divorce in which he has no right of return. But does he have the right to marry her again with a new contract?