Musnad Ahmad 1012:27

Yazid ibn Harun narrated to us, Hammad ibn Salamah informed us, from Jabalah ibn Atiyyah, from Yahya ibn al-Walid ibn Ubadah ibn al-Samit, from his grandfather Ubadah ibn al-Samit, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever goes on a military expedition in the way of Allah, and he does not intend in his expedition except for a hobbling rope, then he shall have what he intended."