Maliks Muwatta Book 30, Hadith Number 10.
Section : Suckling of the Young.
Yahya related to me from Malik that Ibrahim ibn Uqba asked Said ibn al-Musayyab about suckling. Said said, “All that occurs in the first two years, even if it is only a drop, makes haram. Whatever is after two years, is only food that is eaten.”
Ibrahim ibn Uqba said, ”Then I asked Urwa ibn az-Zubayr and he told me the same as what Said ibn al-Musayyab said.”