The Messenger of Allah ﷺ said, "Whatever of the lower garment hangs below the ankles is in the Fire," meaning the izar.
حدثنا محمد بن جعفر حدثنا شعبة قال سمعت سعيد بن أبي سعيد المقبري يحدث
قال رسول الله ﷺ ما أسفل من الكعبين ففي النار يعني الإزار
Its isnad is sahih. Bukhari transmitted it with this wording, 7/183, as did Nasai, 8/207, Ibn Majah, no. 3573, and Ibn Abu Shayba, 8/204.