The Rulings of Hijab
In the Tasif of Ibn Kathir 24.31 book 7 page 67:
This is command from Allah to the believing women, and jealousy on His part over the wives of His believing servants. It is also to distinguish the believing women from the women of the Jahiliyyah and the deeds of the pagan women. The reason for the revelation of this Ayah was mentioned by Muqatil bin Hayyan, when he said "We heard- and Allah knows best- That Jabir bin Abdullah Al Ansari narrated that Asma bint Murshidah was in a house of hers in Bani Harithah, and the women started coming in to her without lower garments so that the anklets on their feet could be seen, along with their chests and forelocks. Asma said: "How ugly this is!" Then Allah revealed:
(And tell the believing women to lower their gaze)
meaning, from that which Allah has forbidden them to look at, apart from their husbands.
Some scholars said that it is permissible for women to look at non Mahram men without desire, as it was recorded in the Sahih that the Messenger of Allah ( sallallaahu ’alayhi wa sallam) was watching the Ethiopians playing with spears in the Masjid on the day of Id, and Aishah the Mother of the believers was watching them from behind him and he was concealing her from them, until she got boarded and went away.
(and protect their private parts). Sa' id bin Jubayr said: "From immoral actions." Abu Al Aliyah said: "Every Ayah of the Qur'an in which protection the private parts is mentioned means protecting them from Zina, except for this Ayah
(and protect their private parts), which means protecting them from being seen by anybody.
(and not to show off their adornment except that which is apparent),
means, they should not show anything of their adornment to non Mahram men except for whatever it is impossible to hide. Ibn Mas'ud said: "Such as clothes and outer garments,"
