Musannaf Ibn Abi Shayba 26:451

Abu al-Ahwas narrated to us, from Abdullah ibn Sharik, from Bishr ibn Ghalib, who said: Ibn al-Zubayr met al-Husayn ibn Ali and said: "O Abu Abdullah, give us a legal opinion regarding the newborn who is born in Islam." He said: "His stipend and his provision have become obligatory."