The Ruling on Selling Over One’s Brother’s Sale and Buying Over One’s Purchase

Question:
Honorable Shaykh, may Allah inform you, the Prophet (peace and blessings be upon him) forbade a man from selling over his brother’s sale. If the seller of the item is not a Muslim, is it permissible for me to sell over his sale? Likewise, if the buyer is a disbeliever, is it permissible to buy over his purchase?

Answer:
No, it is not permissible to wrong people. Wronging people in transactions is not permissible, even if they are disbelievers, because the Muslim is required to be just. Allah the Exalted said: So the Muslim must be truthful in his dealings with Muslims and with disbelievers. Even if he is truthful in his dealings, this becomes a cause for calling disbelievers to Islam. But if he is corrupt in his dealings, this drives people away from Islam. Truthfulness is required; truthfulness in dealings is required with Muslims and with disbelievers. The wealth of a disbeliever is not lawful except if he is a combatant. If he is a combatant, his wealth becomes lawful not through deception or theft, but through jihad and war spoils. His wealth becomes lawful through war spoils and jihad. As for you stealing the wealth of disbelievers or seizing it by force and taking it, this is not permissible. Rather, the wealth of combatant disbelievers becomes permissible through jihad and war spoils. Yes.