Abdullah bin Tawus عبد الله بن طاوس · The Book of Financial Transactions

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

he did not see anything wrong with it even if it was on credit.

"I came to the Prophet and said: 'Wait, I want to ask you something. I sell camels in Al-Baqi with a price set in Dinars but I accept Dirhams instead.' He said: 'There is nothing wrong with it if you take the price on that day, still unfinished business between you both (buyer and seller)"'

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