Imam Malik's Muwatta, Chapter: Divorce

Yahya related to me from Malik that Ibn Shihab said that he had heard Said ibn al-Musayyab, Humayd ibn Abd ar-Rahman ibn Awf, Ubaydullah ibn Abdullah ibn Utba ibn Masud, and Sulayman ibn Yasar all say, that they had heard Abu Hurayra say that he had heard Umar ibn al-Khattab say, "If a woman is divorced by her husband once or twice, and he leaves her until she is free to marry and she marries another husband and he dies or divorces her, and then she marries her first husband, she is with him according to what remains of her divorce." Malik said, "That is what is done among us and there is no dispute about it."