Musnad Ahmad 700:1

Waki' narrated to us, Hammad bin Salamah narrated to us, from Abu al-'Ushara', from his father, who said: I said, "O Messenger of Allah, is the slaughter (dhabihah) only in the throat or the upper chest (al-labbah)?" He said, "If you were to stab it in its thigh, it would suffice you."