Musnad Ahmad 938:56

Kathir narrated to us, Ja'far narrated to us, Thabit ibn al-Hajjaj narrated to us, he said: Zayd ibn Thabit said: "The Messenger of Allah, peace and blessings of Allah be upon him, forbade us from *al-mukhabarah*." I said: "And what is *al-mukhabarah*?" He said: "To rent out the land for a half, or a third, or a quarter."