and grain that has hardened while still in its ear.
Another condition is that the price be known: if the vendor says, “I sell it for its label price (1),” or “for whatever price the bidding stops at” (2) and the like, or “for one thousand, partly in gold and partly in silver,” the sale is invalid. It is, however, valid to sell a piece of cloth or similar goods on the basis of “each cubit for one dirham,” though not by saying, “from it, each cubit for one dirham” (3).
If someone sells, in a single transaction, both a known item and an unknown one, the contract is valid for the known item in proportion to its share—so long as the unknown can still be determined; otherwise, and if he has not stated the price of each, the entire sale is void. Likewise, if he sells an undivided share that he co-owns with another person, or his own slave together with someone else’s slave of equal value without that person’s permission, or includes a free man (4), or sells vinegar together with wine, the sale stands with respect to what he actually owns, in proportion to its share, while the purchaser retains the option to rescind.
Section
A sale concluded by someone on whom the Friday prayer is obligatory after the second call to prayer is invalid unless a necessity requires it; marriage and all other contracts, however, remain valid.
It is not permissible to sell raisins—or anything similar—to someone who will use them to make wine, nor to sell weapons in times of civil strife, nor to sell a Muslim slave to a non-Muslim unless the latter intends to set him free. If the slave embraces Islam while in the non-Muslim’s possession, the buyer is compelled to divest himself of ownership, nor