A husband deputized another person to divorce his wife on his behalf according to the Sunnah (whatever is reported from the Prophet) and the man did. Later, the husband revoked the divorce.
He is asking whether the revocation is valid or not.
If the reality is as mentioned, that the husband has deputized another person to divorce his wife (and he specified her) according to the Sunnah and the man has done so by proxy, this divorce will be considered a revocable divorce if it is not the third one and it is not in return for a consideration. This means that the husband has the right to take his wife back in marriage as long as she has not completed her `Iddah (woman's prescribed waiting period after divorce). However, if this is the third time of divorce, the woman will not be lawful for him unless she marries another man and this marriage ends lawfully. Moreover, if this divorce is in return for a consideration and it is not the third time of Talaq, it will be lawful for him to take her back in marriage with a new marriage contract and a new Mahr (mandatory gift to a bride from her groom), (Part No. 20; Page No. 237) provided that she gives her consent to remarry him and all the conditions and pillars of marriage are fulfilled. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.