The Prophet ﷺ said, "Allah does not look at the one who lets his lower garment hang below his ankles."
عن النبي ﷺ قال: إن الله عز وجل لا ينظر إلى مسبل الإزار.
Nasai (5332) and Ahmad (2955) both narrated it from the hadith of Ashath bin Abu Shatha, who said, "Saeed bin Jubayr narrated to me, from Ibn Abbas," and he mentioned it. Its isnad is sahih.