Hajjaj bin Muhammad al-Musaysi حجاج بن محمد المصيصي الأعور · The Book of Financial Transactions

"The Messenger of Allah forbade meeting (the traders on the way) a Muhajhir selling for a Bedouin, keeping the milk in the udder of an animal (so as to increase its price), artificially inflating prices, a man to urge the cancellation of sale already agreed upon and a woman to ask that her sister (in faith) be divorced."

'The Messenger of Allah paid off what he owed me, and gave me more."

the Messenger of Allah forbade selling loyalty or giving it away. (Shah)

"The Messenger of Allah said - among the things that be forbade - 'And the price of a dog."