Muwatta Malik, Book 30, Hadith 1278 (In-Book) ⓘ
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."
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ ثَوْرِ بْنِ زَيْدٍ الدِّيلِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، أَنَّهُ كَانَ يَقُولُ مَا كَانَ فِي الْحَوْلَيْنِ وَإِنْ كَانَ مَصَّةً وَاحِدَةً فَهُوَ يُحَرِّمُ .
also referenced under: Book 30, Hadith 4 (USC-MSA)