Is selling a commodity – after agreeing with a buyer on a price that does not suit the seller – to another buyer who offers a higher price considered to be the bidding (sawm) that is Islamically forbidden? And what are the consequences for the seller if his action falls under bidding (sawm) and he was unaware of the ruling?

Bidding over another's bid is prohibited if there has been an agreement and mutual consent to sell, as the Prophet, peace and blessings be upon him, said: "A Muslim should not bid over the bid of his brother, nor should he propose over his brother's proposal." Its meaning is that the buyer and seller agree on the sale and price, then another comes and offers to buy it. As long as the act was done out of ignorance of the ruling, there is no sin on the doer, and the sale is valid according to the majority of scholars.