Musnad Abu Ya'la al-Mawsili 152:78

Abu Khaythama narrated to us, Jarir narrated to us, from Mughira, who said: A net (shibak) was mentioned to Ibrahim. He said: We asked Alqama about that, and he narrated to us from Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) cursed the consumer of usury and the one who pays it. He (Mughira) said: I said, "And its two witnesses and its scribe?" He said: "We only narrate what we have heard."