(119) Chapter: The Description of the Length of the Qamees' Sleeves, the End of the Turban, and Prohibition of Wearing Long Garments Out of Pride and Undesirability of Wearing Them Without Pride

Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "The lower garment of a believer should be half way below the knees. He is guilty of no sin if they are up to the ankles. That which is below the ankles is in the Fire (of Hell). Allah will not look at one who allows his lower garment to trail out of vanity.

[Abu Dawud].

Commentary: This Hadith says that a garment like trousers, pajamas, etc., should, properly speaking, go down up to the middle of the shanks. However, it is permissible to lower it up to the ankles which should remain uncovered.
This commandment is for men alone. On the contrary, women are required to cover not only their ankles but also their feet, particularly when they go out.