The Messenger of Allah ﷺ said, "Whatever part of the lower garment hangs below the ankles will be in the Fire."
أخبرنا إسمعيل بن مسعود قال حدثنا خالد وهو ابن الحارث قال حدثنا هشام عن يحيى عن محمد بن إبراهيم قال حدثني أبو يعقوب أنه سمع
قال رسول الله ﷺ ما تحت الكعبين من الإزار ففي النار
Sahih. Ahmad reported it: 2/255, from the hadith of Hisham Dastawai, with this same chain, and Uzai followed him in narrating it, in Ahmad: 2/287.Yahya bin Abu Kathir stated clearly that he heard it directly. Muhammad bin Ibrahim is Ibn Harith. "Abu Yaqub" is a mistake, the correct form is "Ibn Yaqub," and he is Abdul-Rahman bin Yaqub, the freed slave of Hurqah, the father of Ala (Musnad Ahmad: 2/255). The hadith is also found in Kubra, no. 9711.