"...then either maintain (them) in honor or let (them) go in...
"...then either maintain (them) in honor or let (them) go in kindness...." Therefore, the third divorce has not any revocation, because when they had two occasions of dispute and divorce and then peace and revocation were fulfilled, they must put an end to it. The purpose of the phrase: 'let (them) go in kindness' is that the husband ought to pay that woman her rights fully and does not let himself say unsuitable words behind her back after he separates from her.
He must not make the attitude of other people bad against her and lets her retain the possibility of marriage. Hence, separation should also be accompanied with kindness and benevolence. That is why the verse continues saying: "...It is not lawful for you to take anything of what you have given them,…" It is not lawful for the husband to take or withhold anything out of what he has given or promised to give i.e. 'Mahr' or dower to the wife.
The dower amount is usually large and much of it usually remains unpaid by the husband, the payment of the dower amount, particularly when the divorce is pronounced, is another check upon the husband resorting to an indiscriminate and unnecessary divorce of his wife. So, at the time of separation and divorce, the husband is not allowed to take back from the woman forcefully what he has given her as a marriage-portion.
In the next part of the verse, it points to the divorce of khul', and says that it is only in one phase that taking the dower is possible. It is in the case that the woman does not want to continue the conjugal life and they both fear that they are not able to observe the limits of Allah in that kind of life.
"...unless both fear that they cannot keep (themselves) within Allah's bounds..." Under this law the wife may seek to get freed of the wedlock by returning the dower to husband, if she has already received it, or to forgo it, if it be still due to her and take the divorce of khul' from Hakim-i-Shar', viz. the Islamic judge.
Then it says: "...and if you fear that they cannot keep (themselves) within Allah's bounds, it is no sin on either of them about what she gives up to get herself freed (from the wedlock)." In this phase, the origin of separation is, in fact, the wife. So, she must pay the indemnity of this action and let the man, who is willing to live with her, marry another lady with the same marriage-portion.