TASATTUR - تستر
Derived from the same root of satr (ستر ). One of the names of Allah, As-Sattar الستار , which means The Concealer or Veiler, One Who conceals the sins is also derived from the same root.
Literally: A being or becoming veiled. Curtained. Hidden. Shrouded; concealment. To cover. To veil. To drape. To conceal one's self. Veiling.
In Sharî’ah: For men and women, not showing the prohibited parts of their bodies to non-mahrams who are specified in the Qur’an.
“The Sunnah as-Saniyyah is adab. There is no matter among them beneath which a nûr, and adab, is not to be found. Ar-Rasûl Al-Akram ‘Alayhissalâtu Wassalâm decreed اَدَّبَنِى رَبِّى فَاَحْسَنَ تَاْدِيبِى , that is: "My Rabb bestowed me adab beautifully and instructed me of the adab" Yes, one who studies the Prophet's biography and knows his Sunnah as-Saniyyah will certainly understand that Janâb-i Haqq gathered together in His Habib1 all the varieties of adab. One who gives up the Sunnah as-Saniyyah abandons adab. He verifies the rule, 2 بِى اَدَبْ مَحْرُومْ بَاشَدْ اَزْ لُطْفِ رَبْ and falls in non-adab in a way that causes him the loss.”
Question: How can there be adab in the face of al-‘Allâm ul-Ghuyûb, Who sees and knows everything and from Whom nothing can be hidden? Situations which cause shame or embarrassment cannot be concealed from Him. One sort of adab is tasattur, that is veiling the states which cause to disgust. But nothing can be hidden from the sight of al-‘Allâm ul-Ghuyûb.
Firstly: Giving it the greatest importance, As-Sâni’ Zuljalâl wants to show His art as beautiful; He veils detestable things; and He attracts attention to His ni’mahs by decorating them. So too, He wants to show His creatures and ‘abds as beautiful to other conscious beings. Their appearing in ugly situations is a sort of rebellion against His Names like Jamîl, Muzayyin, Latîf, and Hakîm, and is contrary to adab. Thus, the adab of the Sunnah as-Saniyyah is to assume a manner of pure adab within the bounds of As-Sâni’ Zuljalâl's Names.
Secondly: As a doctor, a doctor may examine the most private member of a non-mahram, and if necessary it may be shown to him, and this may not be said to be contrary to adab. Indeed, it may be said that the adab of medicine requires this. But the same doctor may not look to those non-mahram through his title of manhood, or under the name of hoja or preacher, and adab cannot issue a fatwa permitting it to be shown. To show it to him in such a way would be a lack of hayâ.
In just the same way, As-Sâni’ Zuljalâl has numerous Names, and each Name has a different manifestation. For example, just as the Name of Ghaffâr requires the existence of sins and Sattâr, the existence of faults, so too, the Name of Jamîl does not wish to see ugliness. Names pertaining to Jamâl and Kamâl like Latîf, Karîm, Hakîm, and Rahîm require that beings be in the most beautiful form and best possible situations. And those Names pertaining to Jamâl and Kamâl want to display their beauties in the view of Malâikah, rûh beings, jinn and man through the beautiful adab and fine conduct of beings. Thus, the âdâb of the Sunnah as-Saniyyah are the signs of this elevated âdâb, and its principles and samples.” The Eleventh Flash - Seventh Subtle Point