Is it permissible to deal with Jews, or companies owned by them, or companies that have branches in Israel, even though the Prophet, may Allah’s prayers and peace be upon him, dealt with Jews and mortgaged his shield with a Jew?

The fundamental principle is the permissibility of buying and selling with Jews and others. This is evidenced by the dealings of the Prophet, peace and blessings be upon him, and his Companions with the Jews of Medina. It is also permissible to buy and sell with belligerent disbelievers, and there is a consensus among Muslims on the permissibility of dealing with Dhimmis and other disbelievers, unless what they possess is definitively prohibited. However, it is not permissible for a Muslim to sell weapons, war machinery, or anything that aids them in establishing their religion, to people at war. Jihad against enemies is legitimate, both financially and physically, and this includes weakening their economy. Muslims must cooperate in righteousness and piety and help their brethren with everything that strengthens Islam and weakens the belligerent disbelievers. Whoever boycotts the goods of belligerent disbelievers with the intention of demonstrating disavowal of them and weakening their economy will be rewarded. Whoever deals with them, adhering to the original principle of permissibility, incurs no blame. The fundamental principle is the permissibility for a Muslim to purchase his needs from a Muslim or a disbeliever. However, preferring to purchase from a disbeliever without a valid reason is forbidden, as it involves showing allegiance to disbelievers, unless there are compelling reasons that necessitate it.