Yahya related to me from Malik from Ibn Shihab from Amr ibn ash- Sharid that Abdullah ibn Abbas was asked whether, if a man had two wives, and one of them nursed a slave-boy, and the other had nursed a slave-girl, could the slave-boy marry the slave-girl. He said, "No. The husband is the same."  

عَنْ رَجُلٍ كَانَتْ لَهُ امْرَأَتَانِ فَأَرْضَعَتْ إِحْدَاهُمَا غُلاَمًا وَأَرْضَعَتِ الأُخْرَى جَارِيَةً فَقِيلَ لَهُ هَلْ يَتَزَوَّجُ الْغُلاَمُ الْجَارِيَةَ فَقَالَ لاَ اللِّقَاحُ وَاحِدٌ  

[Machine] A man had two wives, one of whom breastfed a boy and the other breastfed a girl. It was said that the boy will marry the girl, but he said, "No, they have the same breastfeeding."  

رَجُلٍ كَانَتْ لَهُ امْرَأَتَانِ فَأَرْضَعَتْ إِحْدَاهُمَا غُلَامًا وَأَرْضَعَتِ الْأُخْرَى جَارِيَةً فَقِيلَ يَتَزَوَّجُ الْغُلَامُ الْجَارِيَةَ فَقَالَ لَا اللِّقَاحُ وَاحِدٌ