Muhammad bin Rafa'i محمد بن رافع · The Book of Financial Transactions

" The Messenger of Allah ruled that what a slave earns belongs to his guarantor."

the Prophet forbade artificially inflating prices.

"When the Prophet (ﷺ) came to Al-Madinah, he called for a scale and weighed (something) for me and gave me more."

"A slave came and gave his pledge to the Messenger of Allah to emigrate, and the Prophet did not realize that he was a slave. Then his master came looking for him. The Prophet said; 'Sell him to me.' So he bought him for two black slaves, then he did not accept until he had asked; 'Is he a slave?'''

"The Messenger of Allah said: 'Whoever sets free his share of a slave, and he has sufficient wealth to set him free completely by paying the price of the slave, then he should set him free with his own wealth."'