If a husband says to his wife: "I have given you ownership over yourself," then explains it as an authorization for divorce, and then the wife says: "We entrust you to Allah, with Whom nothing is lost," is this considered a divorce?

A man's statement to his wife, "I have given you ownership of yourself" (malaktuki nafsaki) or "I have placed the 'isma (right to divorce) in your hand" is not a divorce in itself. Rather, it is an authorization for her regarding the matter of divorce. If the wife, by saying "We entrust you to Allah" (nastawdi'uk Allah), intended that she was taking the divorce, then a single, revocable divorce has occurred, unless the husband had given her the right to more than that. This applies if consummation has taken place. Divorce by delegation (al-talaq (definition) bil-tamleek), if it occurs after consummation, is revocable, unless it is in exchange for a financial consideration, in which case it becomes irrevocable. If this is the first or second divorce, you may take her back before her waiting period (iddah (definition)) expires without a new marriage contract. The majority of scholars are of the view that divorce by delegation is restricted to the session (majlis) in which it is made, whereas the Hanbalis hold that it is not restricted to the session.