It wasnarrated from 'Aishah that the Prophet (ﷺ) said, concerninghowlong a woman's hem should hang down:
"A hand span." 'Aishahsaid:"This may show her calves." He said: "Then a forearm'slength." (ES)
English reference (ES): Vol. 4, Book 32, Hadith 3583 (ES)
Arabic reference (ES): Book 32, Hadith 3714 (ES)