Is a divorce considered to have occurred if a man tells his wife: "You are divorced if you leave the house," and the wife leaves the house before reading the message?

If the divorce letter was written with the intention of effecting divorce, and the wife did not learn of its content until after she left the house, and she cared about the husband's oath such that if she had known, she would not have left, then in this case, divorce does not occur according to some scholars. The husband should not be hasty with words of divorce, and there should be respect and understanding between the spouses.