Yahya related to me from Malik that he had heard that Umar ibn
al-Khattab, Abdullah ibn Umar, Abdullah ibn Masud, Salim ibn Abdullah,
al-Qasim ibn Muhammad, Ibn Shihab,and Sulayman ibn Yasar all said, "If
a man has vowed to divorce his wife before marrying her and then he
breaks his vow, divorce is obligatory for him when he marries her."