Sunan Ibn Majah
Hadith #2082
lt was narrated that Abul Hasan, the freed slave of Banu Nawfal, said:""Ibn 'Abbas was asked about a slave who divorces his wife twice, then (they are freed). Can he marry her? He said: 'Yes.' It was said to him: 'On what basis?' He said: 'The Messenger of Allah (ﷺ) passed such a judgement .' "" (D a' if)