Musnad Ahmad 27:377

Al-Aswad ibn Amir narrated to us, Abu Bakr informed us, from al-A’mash, from ‘Ata’ ibn Abi Rabah, from Ibn Umar, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: "When—meaning when people become stingy with the dinar and the dirham—they trade with 'inah (a form of usurious transaction), follow the tails of oxen, and abandon jihad in the way of Allah, Allah will send down upon them a trial, and He will not lift it from them until they return to their religion."