"Avoid jealousy between yourselves, do not outbid one another (with a view to raising the price), do not harbor hatred against one another, do not bear enmity against one another, one of you should not enter into a transaction when the other has already entered into it; and be fellow brothers and slaves of Allah. A Muslim is a Muslim's brother. He does not wrong, desert or despise him. Piety is found here (pointing three times to his chest), despising his Muslim brother is enough evil for any man to do. Every Muslim's blood, property and honor are unlawful to be violated by another Muslim."

Related by Muslim.