During the third century Hijri, the Qaadi (judge) of Rayy and Ahwaaz, Musa bin Ishaaq, sat to adjudicate people's disputes. Among the litigants was a woman who claimed five hundred dinars Mahr from her husband.
The husband denied the claim.
The Qaadi said to the husband, "Bring your witnesses."
The husband said, "I have brought them."
The Qaadi said to one of the witnesses, "Look at the wife so you may point her out during testimony."
The witness stood up and said to the woman, "Stand."
Upon this, the husband said, "What do you want from her?"
The husband was told, "It is necessary that the witness sees your wife unveiled so that he may know that it is your wife."
The husband detested his wife unveiling her face for the witnesses in public. He screamed, saying, "I make the Qaadi my witness that this Mahr of my wife is an obligation on me, and she must not unveil her face!"
When the wife heard this, she thought it was wonderful that her husband
disapproved of her unveiling her face before the witnesses, and was protecting her from the sight of people.
She too screamed at the Qaadi, "I make you a witness that I have granted my Mahr to him, and have absolved him in this Dunyaa and the Aakhirah!"
The Qaadi said to those around him, "Record this as a moral standard."
Source: Tarbiyat Al-Awlaaad Fil Islaam