Yahya related to me from Malik from Thawr ibn Zayd ad-Dili that Abdullah ibn Abbas said, "The milk which a child under two years old sucks, even if it is only one suck, makes the foster relatives haram."
Muwatta Malik Book 30, Hadith 4
← Previous Hadith Yahya related to me from Malik from Ibn Shihab from Urwa ibn az- Zubayr that A'isha umm al-muminin told him that Aflah, the brother of Abu'l-Quays came and asked permission to visit her after the veil had been lowered, and he was her paternal uncle by suckling. She said, "I refusedto give him permission to enter. When the Messenger of Allah, may Allah bless him and grant him peace, came, I told him about what I had done, and he ordered me to give him permission to enter."

Muwatta Malik Book 30, Hadith 3 Next Hadith → 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."

Muwatta Malik Book 30, Hadith 5