Musnad Ahmad 30:2572

Marwan al-Fazari narrated to us, he said: Hisham al-Dastawa'i informed us, from Yahya ibn Abi Kathir, from Abu Ja'far, from Abu Hurayrah, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The best of faith in the sight of Allah is faith in which there is no doubt, and a military expedition in which there is no misappropriation of spoils, and an accepted Hajj." He said: Abu Hurayrah said: "An accepted Hajj expiates the sins of that year." Marwan said: "I am in doubt regarding it, whether it is from al-Hajjaj al-Sawwaf or from Hisham."