Musnad Ahmad 285:7

Yazid ibn Harun narrated to us, he said: Al-Awwam ibn Hawshab informed us, he said: Ibrahim, the freed slave of Sukhayr, narrated to me, from some of the companions of the Prophet, may God bless him and grant him peace, who said: The Messenger of God, may God bless him and grant him peace, wanted to forbid a type of sale. They said: "O Messenger of God, it is our livelihood." He said: "Then there is no deception." And we used to be called brokers. Then he mentioned the rest of the hadith.