Is it permissible for a man who has divorced his wife three times to take her back, or must she marry another husband?

Scholars agree that if a man divorces his wife and takes her back three times, she becomes irrevocably separated from him (baynunah kubra) and is not lawful for him until she marries another husband. They differ, however, on the issue of uttering three divorces in one phrase. The majority of scholars hold that it counts as three divorces, while some consider it a single divorce. As for divorce pronounced in a state of anger: if the angry person is aware of what he is saying, the divorce takes effect. If he is not aware of what he is saying, his divorce does not take effect. Therefore, if the divorce occurred three times while he was conscious, the wife has become irrevocably separated and is not lawful for her husband until she marries another husband willingly.