Is the sale considered valid if merchandise (light bulbs) that has not yet arrived in the city is purchased, given that both the seller and the buyer know its type, price, and popularity in the market, and that the initiative came from the seller? Does this sale fall under the category of receiving goods before their arrival? Is the buyer sinful as a result? How can he expiate this sin, knowing that the sale took place with the consent of both parties?

It is permissible for a debtor to sell something to pay off his debt, and this is called 'istibdal' (exchange), provided that the object sold is owned by the seller at the time of the contract, and that possession of the sold item takes place at the contracting session. It is not permissible to sell a debt for a debt, such as selling a debt for a commodity whose possession is delayed. As for 'talaqqi al-rukban' (meeting riders), it refers to merchants going out to meet incoming caravans with goods and buying their merchandise from them at cheap prices to sell it at a high price, and this has no relation to the question.