What is the ruling on eating food purchased with money from selling cigarettes? Is it permissible to sell cigarette packs given as gratuities and buy food with their price? And what is the ruling on eating with someone who does that and donating the value of what I ate?

It is impermissible to take, finance, sell, or consume the price of cigarettes, because they are forbidden. The Messenger of Allah, peace and blessings be upon him, said: "Indeed, when Allah prohibits something, He prohibits its price." And every forbidden thing, taking compensation for it is forbidden. As for giving in charity the value of forbidden food, it serves as repentance for what has passed, but it does not absolve its owner from sin in the future.