Narrated Umar ibn Mu'tab:

Abu Hasan, a client of Banu Nawfal asked Ibn Abbas: A slave had a wife who was a slave-girl. He divorced her by two pronouncements. Afterwards both of them were freed. Is it permissible for him to ask her in marriage again? He said: Yes. This is a decision given by the Messenger of Allah (ﷺ).

حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، حَدَّثَنَا عَلِيُّ بْنُ الْمُبَارَكِ، حَدَّثَنِي يَحْيَى بْنُ أَبِي كَثِيرٍ، أَنَّ عُمَرَ بْنَ مُعَتِّبٍ، أَخْبَرَهُ أَنَّ أَبَا حَسَنٍ مَوْلَى بَنِي نَوْفَلٍ أَخْبَرَهُ أَنَّهُ، اسْتَفْتَى ابْنَ عَبَّاسٍ فِي مَمْلُوكٍ كَانَتْ تَحْتَهُ مَمْلُوكَةٌ فَطَلَّقَهَا تَطْلِيقَتَيْنِ ثُمَّ عَتَقَا بَعْدَ ذَلِكَ هَلْ يَصْلُحُ لَهُ أَنْ يَخْطُبَهَا قَالَ نَعَمْ قَضَى بِذَلِكَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏.‏