Hadith 10:849
Abu Bakr narrated to us, he said: Waki’ narrated to us, from al-A’mash, from Ibrahim, who said: The one who has sworn an oath of abstention (from his wife) is made to stand at the expiration of the four months. If he returns (to his wife), then she is his wife. And if he does not return, then it is a single irrevocable divorce.
حدثنا أبو بكر قال نا وكيع عن الأعمش عن إبراهيم قال يوقف المولي عند انقضاء الأربعة فإن فاء فهي امرأته وإن لم يفيء فهي تطليقة بائنة