What is the ruling on selling sportswear to women?

The fundamental principle is the permissibility of selling women's clothing. However, it becomes impermissible to sell it if the seller knows that the buyer will use it for ostentatious display (tabarruj) and revealing her charms to non-mahram men. In such a case, the seller becomes an accomplice in sin. The Permanent Committee has stated that anything used in a forbidden manner, or if it is highly probable that it will be used in such a way, its manufacturing, import, and sale are prohibited. Sheikh al-Islam Ibn Taymiyyah said: "Every garment that is likely to be used as an aid to disobedience, it is not permissible to sell it or sew it for someone who will use it to commit disobedience and injustice."