Muhammad bin 'Ubaid al-Tanafasi محمد بن عبيد بن أبي أمية الطنافسي · The Chapters on Business Transactions

"The importer is blessed with provision and the hoarder is cursed."

the Messenger of Allah (ﷺ) forbade Mulamasah and Munabadhah. (Sahih) Sahl added: "Sufyan said: 'Mulamasah means when a man touches something with his hand without seeing it, and Munabadhah means when he says: "Toss me what you have, and I will toss you what have."

"Let one of you not undersell another."