Yahya related to me from Malik from Nafi that Abdullah ibn Umarsaid, "When a man divorces his wife and she begins her third period,she is free from him and he is free from her."Malik said,"This is how things are done among us." (IT)
USC-MSA web (English) reference: Book 29, Hadith 58 (IT)
Arabic reference (IT): Book 29, Hadith 1219 (IT)