Abu Huraira reported Allah’s Messenger ﷺ as saying:
Do not envy one another, 

do not artificially inflate prices, 

do not hate one another, 

do not turn away from one another, 

do not undercut one another (don’t enter into a transaction when the others have entered into that transaction). 

Be, O slaves of Allah, brothers. 

The Muslim is the brother of his fellow-Muslim. He does not wrong him, forsake or despise him. Piety (Taqwa) is here” – and he pointed to his chest three times. “It is sufficient sin for a man to despise his Muslim brother. A Muslim is unlawuful to another Muslim, his blood, his wealth and his honor.”

[Sahih Muslim, Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship, Hadith: 2564 (6541)]

Despise: to feel a strong dislike for someone or something because you think that that person or thing is bad or has no value: The two groups despise each other