Musannaf Ibn Abi Shayba 13:2306

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Hisham narrated to us, from Qatadah, from Sa’id bin Abi al-Hasan, who said: "I am indeed amazed at the one whom people seek for judgment until he judges between them, then he takes a wage for that."