[The Ruling on Selling Tape Recorders, Televisions, and the Like]

The answer—and Allah is the granter of success: There is no objection to buying and selling such items, as well as anything that can be used for both lawful and unlawful purposes.
What is impermissible to sell is that which is made specifically for the unlawful—such as flutes, the ‘ūd (lute), and all other instruments of prohibited entertainment and the like. It is also impermissible to sell weapons to those who are at war against the Muslims, whether they are unbelievers or rebellious aggressors.
The evidence for what may not be sold: our statement that it is impermissible to sell what is made specifically for the unlawful, and that selling weapons to those waging war is prohibited, is what the outward sense of the Noble Book indicates. Among that is Allah’s saying: “And do not cooperate in sin and aggression.” [Al-Mā’idah:2], and similar passages in the Qur’an.
There is no doubt that providing instruments of entertainment and selling them is a major cause of spreading corruption and the proliferation of wrongdoing; and selling weapons to combatants strengthens their side and reinforces them, leading to increased aggression against the Muslims and harm to them—and that is sufficient to count as aiding aggression.
The evidence for what we stated in the first part of the answer is that there is no definitive impediment to selling such items except the suspicion that they will be used for the unlawful, and that is not a barrier. The proof is what is well known about the Prophet—May Allah bless him and his family and grant them peace—that he used to transact in Madinah with the Jews in buying and selling, even though he—May Allah bless him and his family and grant them peace—knew that they engaged in usury and invested their wealth in it. Allah did not forbid him—May Allah bless him and his family and grant them peace—from dealing with them. Likewise, his Companions during his time—May Allah bless him and his family and grant them peace—had many dealings with the Jews, and he—May Allah bless him and his family and grant them peace—did not censure them for those dealings; rather, he approved them and himself—May Allah bless him and his family and grant them peace—engaged in them, as we have mentioned.
The Prophet—May Allah bless him and his family and grant them peace—and the Companions knew, too, how the Jews used their wealth in unlawful ways. Allah, Exalted is He, described them in His Book, saying: “…and [for] their taking of usury while they had been forbidden from it, and their consuming of people’s wealth unjustly.” [An-Nisā’:161], and “…devourers of illicit gain (suḥt) …” [Al-Mā’idah:42], and other descriptions Allah gave them—of turning people away from the path of Allah, spreading corruption on earth, etc.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2