What is the ruling on selling vegetables and fruits to someone who uses them in alcohol gatherings, and is it permissible to refuse to sell them even if it causes harm to the seller?

If it is meant that fruits are sold to people who consume them in gatherings where alcoholic beverages are drunk, then there is no harm in the sale, as this is not considered aiding in sin. However, if it is meant that the fruits are used in the pressing of wine, then if it is known or highly probable that they will be used for that purpose, selling them is not permissible. But if it is known or highly probable that they will be used for permissible purposes, then there is no harm. In all other cases, the default ruling is permissibility. Therefore, it is obligatory to sell the fruits in the latter two cases, and not to sell them in the first case (when they are used in the pressing of wine), while not obeying authorities in selling them to those who press wine.