Musnad Ahmad 1034:200

Yazid ibn Harun narrated to us, Abu Malik informed us, Rib'i ibn Hirash narrated to me, from Hudhayfah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "All good is charity. And indeed, the last thing that the people of Jahiliyyah (the pre-Islamic era) clung to from the words of the Prophethood is: 'If you feel no shame, then do as you wish.'"