Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: Do not practice Najsh (artificially inflating prices), avoid mutual estrangement, do not compete with each other in transactions, avoid envy of one another, do not harbor malice against each other, no one should make an offer over the deal of his brother, a townsman should not sell on behalf of a villager, leave people alone, Allah provides sustenance to some through others, and no woman should stipulate the divorce of her sister as a condition.