Amatul Rahmân Omer:
Prophet! tell your wives, your daughters and women of the believers that (while going out of their houses) they should draw lower upon them the portions of their (loose) outer coverings from over their heads on to their bosoms (so as to veil therewith the arms, the neck, the hair and ornaments worn over them). This practice is more likely to help them to be distinguished (from other women who make a display of their beauty and ornamentation) and so saves them from trouble. Allâh is Great Protector, Ever Merciful.
