Sayyiduna Hudhayfah (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings of Allah be upon him) placed his blessed hand on the middle part of his (or their) shin and said: This is the place for the lower garment. If you do not accept, then lower it further. If you still do not accept, then there is no right for the lower garment below the ankles. (That is, it should be above the ankles.)
Hadith Referenceصحیح ابن حبان / كتاب اللباس وآدابه / 5448
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - انظر (5421). تنبيه!! رقم (5421) = (5445) من «طبعة المؤسسة». - مدخل بيانات الشاملة -.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده قوي