Musannaf Ibn Abi Shaybah

Hazrat Anas bin Malik (may Allah be pleased with him) narrates that a slave woman came to Hazrat Umar bin Khattab, whom he recognized because of some Muhajir or Ansari. She had a large sheet on her, with which she had veiled herself. Hazrat Umar asked her, "Have you been freed?" She replied, "No." He then asked, "Then why are you wearing this sheet?" Take it off your head; the sheet is for the heads of free believing women." At this, the slave woman started making excuses. So Hazrat Umar struck her with his whip on her head and removed her sheet.