Riyad Us-Saliheen (Gardens of the Righteous)

Chapter 331
Prohibition of Describing the Charms of a Woman to a man without a valid reason approved by the Shari'ah

1742. Ibn Mas`ud (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said, "No woman should touch another woman's body and then describe the details of her figure to her husband in such a manner as if he was looking at her.''
[Al-Bukhari].

Commentary:  "Mubashirah'' means "meeting of two bodies'' and here it signifies that one should not see another person's body. Here, it is used in its literal as well as metaphorical sense. What it really means is that neither a woman should see the body of any other woman nor should she touch her own body with the body of some other woman, for if she does so, she will come to know the physical qualities of the other woman which she may disclose to her husband. Such disclosures may induce her husband to mischief and eventually ruin her own life. One is allowed, however, to disclose a woman's charms to a man who intends to marry her.