What is the ruling on selling a commodity, giving a gift, or teaching knowledge to someone who is thought to use it for both lawful and unlawful purposes? And does sin befall one who creates an educational website if its information is used for unlawful matters?

Selling or gifting something intended for an unlawful purpose is impermissible according to the majority of scholars, in contrast to the Hanafis. The majority holds that anything intended for a haram (definition) (unlawful) purpose, or that leads to disobedience (ma'siyah), is forbidden. This includes selling anything when it is known or strongly suspected that the buyer will use it for something impermissible.

Examples include: selling a female slave to people of corruption, selling land to be used as a church or a tavern, selling wood to someone who will make a cross, selling weapons to belligerents or highwaymen, and renting out a house for selling alcohol. It is also stipulated that it is forbidden to sell food to a non-Muslim if it is known or strongly suspected that they will eat it during the day in Ramadan (definition), and to sell drugs to someone who is suspected of using them in an unlawful manner.

The Hanafis differed on some issues, believing it permissible to sell something where the act of disobedience is not inherent in the item itself, such as selling a ram that butts, but they forbade selling weapons to those engaged in sedition. The two companions (Imam Abu Yusuf and Imam Muhammad) among the Hanafis considered it makruh (definition) (disliked) as it constitutes aiding in disobedience.

The prohibition is conditional upon certainty or strong suspicion that the item will be used for an unlawful purpose. As for designing a website to teach programming to the general public, it does not fall under this ruling, because there is no certainty or strong suspicion of its use for disobedience, and the ruling remains based on the principle of permissibility.