What is the ruling on selling adulterated kohl out of ignorance, and is the seller sinful if the supplier adulterated it after the first batch was verified?

Allah has forbidden cheating and deception, and has made sincerity obligatory in matters of religion and transactions. Whoever cheats is not among the Muslims. However, as long as the buyer was unaware of the cheating, there is no sin upon him; rather, the sin is upon the one who cheated him. The issue of compensation here requires judicial review to understand the specifics of the case and determine who is to be blamed and held liable for compensation.

For instance, if someone gives poisoned food to another person to serve to their guests, and the second person is unaware that the food is poisoned, then the liability for compensation falls upon the one who poisoned the food, not upon the one who presented it. The same applies to someone who sells a defective item that causes harm to others without the buyer's knowledge of the defect; in this case, the liability for compensation falls upon the original seller.