Musannaf Ibn Abi Shayba 28:983

Isa ibn Yunus narrated to us, from al-Awza'i, from Wasif ibn Abi Humayl, from Abu Bakr, from Mujahid, who said regarding the *habis* (endowed) animal that is with a man: If it produces offspring and they increase beyond its value, he said: "Whatever increases is *habis* (endowed) along with it."