in many forms, so the subject of dispute is restricted from it by our evidence. As for their argument that 'the sale is completed with its conditions [8] and pillars,' we say: But there exists an impediment to it. If this is established, then the sale is prohibited and invalid only if the seller knows of the buyer's intention for that, either through the buyer's own words or through circumstances specific to him that indicate that. However, if the matter is ambiguous—such as if he sells them to someone whose state he does not know, or to someone who makes both vinegar and wine, and he has not uttered what indicates the intention for wine—then the sale is permissible. If the prohibition is established, the sale is invalid; it is also possible that it is valid, which is the school of al-Shafi'i, because what is prohibited in that is the intention behind the contract, not the contract itself, so it does not prevent the validity of the contract, just as if one were to conceal a defect. Our position is that he entered into a contract for an object for the purpose of disobeying Allah, so it is not valid, like leasing a slave girl for adultery or singing. As for concealment of a defect, the prohibition is on the act [of concealment], not the contract. Furthermore, since the prohibition here is for the right of Allah Almighty, it invalidates the contract, like selling a dirham for two dirhams, and it differs from concealing a defect, as the latter is for the right of a human being.

Section: This is also the ruling regarding everything that is intended [9] for something unlawful, such as selling weapons to people at war, or to highway robbers, or during civil strife (fitna); selling a slave girl for singing, or leasing her for that purpose; or leasing one's house to be used for selling wine, or to be taken as a church, or a fire temple, and similar things. This is prohibited, and the contract is invalid, for the reasons we have previously mentioned. Ibn Aqil said: Ahmad, may Allah have mercy on him, has explicitly stated rulings that serve to highlight this. He said regarding the butcher and the baker: If he knows that whoever buys from him will serve it to those who drink intoxicants, he should not sell to him. He also said that one who manufactures drinking vessels should not sell them to those who drink from them. He forbade selling silk to men, though there is no harm in selling it to women. It is also narrated from him that he should not sell walnuts to children for the purpose of gambling. Based on his analogy regarding this, eggs [are similar], and thus the sale of all such things is invalid.

Section: It was said to Ahmad: A man died and left behind a singing slave girl and an orphaned child, and he is in need of selling her. He said: He should sell her as being an untainted slave (sadhiqa). It was said to him: But she is worth thirty thousand dirhams, and if she is sold as an untainted slave, she is worth twenty dinars. He replied: She should not be sold except as an untainted slave.