Ibn 'Umar (May Allah be pleased with them) reported:
My lower garment was trailing as I passed by Messenger of Allah ﷺ so he said, "Raise your lower garment, Abdullah." I lifted it up and he told me to raise it higher. I complied with his orders and as I was still trying to find the best place (for it), one of the people asked where it should reach and he ﷺ replied, "Half way down the knees."

[Muslim].

وعن ابن عمر رضى الله عنهما قال: مررت على رسول الله ﷺ وفى إزاري استرخاء، فقال: "يا عبد الله، ارفع إزارك" فرفعت ثم قال: "زد"، فزدت، فما زلت أتحراها بعد. فقال بعض القوم: إلى أين ؟ فقال: إلى أنصاف الساقين". .