Musnad Ahmad 956:2

Waki' narrated to us, Sufyan narrated to us, from 'Abd al-'Aziz ibn Rufay', from Ibn Abi Mulaykah, from Ibn Hanzalah ibn al-Rahib, from Ka'b, who said: "For me to commit adultery thirty-three times is more beloved to me than to consume a dirham of usury, while Allah knows that I consumed it as usury at the time I consumed it."