If a man divorces his wife and is unsure whether he divorced her three times or once, what is the ruling?

Question : Now, this is the issue.

Answer : If he divorced her and is unsure whether it was three or one, the default is one. This is the position of most of the companions, as the author (may Allah have mercy on him) stated that it is one. Consequently, it is permissible for him to take her back, because it is one, and one divorce allows for taking back. Some scholars, such as al-Khiraqi (may Allah have mercy on him), who is the author of the Mukhtasar on which al-Mughni is a commentary, stated that she does not become permissible for him.
Why? Because taking back is only permissible if one is certain that the divorce was one. In that case, if he takes her back, the taking back is doubtful; the taking back is doubtful. Therefore, the woman does not become permissible to him through it except after another husband. However, we say in our answer that it is a taking back of something doubtful, but the ruling is that it is non-existent, because the default is one.