Is it permissible to sell fuel on the black market if it was received from a gas station at a fixed price, given the large price difference between the station's price and the black market price?

Trading fuel on the black market is prohibited if it harms people, in accordance with the hadith (definition): "There should be no harm nor reciprocating harm." However, if no harm results, there is no objection to an individual selling their share at a price agreed upon by both parties, even if it is much higher than the purchase price, as Islamic law does not specify a limit for profit. Nevertheless, a Muslim should not be greedy and should prioritize ethical and humanitarian considerations, in line with the hadith: "May Allah have mercy upon a man who is lenient when he sells, when he buys, and when he demands his rights."