Musnad Abu Ya'la al-Mawsili 107:23

Zuhayr narrated to us, Yazid bin Harun narrated to us, Muhammad bin Ishaq narrated to us, from Yazid bin Abi Habib, from Abd al-Rahman bin Shamasa, from Uqbah bin Amir, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: "The collector of *maks*—meaning the tithe-collector—will not enter Paradise."