Maliks Muwatta Book 29, Hadith Number 38.

Section : Divorce of Virgins.

Yahya related to me from Malik from Yahya ibn Said from Bukayr ibn Abdullah al-Ashajj from an-Numan ibn Abi Ayyash al Ansari from Ata ibn Yasar that a man came and asked Abdullah ibn Amr ibn al-As about a man who divorced his wife three times before he had had intercourse with her Ata said, “The divorce of the virgin is one. Abdullah ibn Amr ibn al-As said to me, ‘You say one pronouncement separates her and three makes her haram until she has married another husband.'”