Thmamh bin 'Abdullah ثمامة بن عبد الله بن أنس · The Chapters on Business Transactions

"No man earns anything better than that which he earns with his own hands, and what a man spends on himself, his wife, his child and his servant, then it is charity."

"The Messenger of Allah (ﷺ) said: 'Whoever buys a Muhaffalah, (1) he has the choice (of annulling the deal) for three days. If he returns it, then he must also give wheat equal to twice, the amount of its milk, or equal to the amount of its milk."'