Is it permissible for a man to revoke a khul' agreement made with his wife before she repays him the agreed-upon dower?

If the khul' (divorce by mutual agreement) has effectively occurred through annulment (faskh), and only the delivery of the compensation (iwadh) remains, then there is no option [to revoke]. However, if it was merely an agreement for khul' upon the delivery of the compensation without annulment, then this is a promise and not an annulment, and he has the right to retract unless annulment occurs thereafter. And if he says to her: "If you give me the dowry, then I have divorced you through khul'," then according to the Hanbali school, he does not have the right to retract. But according to Ibn Taymiyyah, he has the right to retract if he has not received the compensation. The most cautious approach in the latter case is to conclude a new agreement to resolve the dispute.