Musannaf Ibn Abi Shayba 33:692

Jarir narrated to us, from al-Shaybani, who said: Mu'dad had a brother. He used to go to the market, buy and sell, and spend on his family and on the family of Mu'dad. He said: He used to say, "He is better than me; we are among his family, and he spends on us." And Allah the Exalted knows best.