Musnad Ahmad 956:1

Husayn ibn Muhammad narrated to us, Jarir—meaning Ibn Hazim—narrated to us, from Ayyub, from Ibn Abi Mulaykah, from Abdullah ibn Hanzalah, the one washed by the angels, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A dirham of usury that a man consumes while he knows [it is usury] is more severe than thirty-six acts of adultery."