Etiquettes of Doing Business

20. A number of our people have narrated from Ahmad ibn Muhammad ibn ‘Isa from ibn Sinan from Yunus ibn Ya’qub from ‘Abd al-‘A’la’ ibn ‘A‘yan who has said the following: “I was told about abu Ja‘far عليه السلام, that he disliked two kinds of transactions: ‘Drop the merchandise without turning its other side and receive payment’, and ‘buying merchandise without seeing’.”