Musnad Ahmad 27:558

Yahya ibn Abd al-Malik ibn Abi Ghaniyah narrated to us, Abu Janab informed us, from Shahr ibn Hawshab, from Ibn Umar, from the Prophet, may Allah bless him and grant him peace, who said: "If you abandon Jihad, and take hold of the tails of cows, and trade by *al-inah* (a form of usurious transaction), Allah will surely impose upon you a humiliation in your necks. It will not be removed from you until you repent to Allah and return to what you were upon."