Musannaf Ibn Abi Shayba 18:961

Abu Bakr narrated to us, he said: Abu Khalid narrated to us, from Ibn Jurayj, from Abu al-Zubayr, from Ubayd ibn Umayr, who said: A man who is *al-ayd*—meaning the strong—intends toward a rock or a piece of wood, and he crushes the head of a man with it. And what intention is more intentional than this?