Musannaf Ibn Abi Shayba 13:3167

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: ‘Isa al-Khayyat narrated to us, he said: I asked Sa’id ibn al-Musayyib about a man who hired a porter to carry food for him. He (the porter) placed a load of it at his (the employer's) family, then he (the employer) said: "Look at what you are selling it for, and calculate it against me." Sa’id said: "He owes him food similar to his food."