Musnad Abu Ya'la al-Mawsili 118:80

Abu Ali al-Hasani narrated to us, Ibn Abi Uways narrated to us, my father narrated to me, from Musa ibn Uqbah, from al-Zuhri, from Anas, who said: They said, "O Messenger of Allah, shall we not assist in the ransom of al-Abbas?" He said, "Not even with a single dirham."