,,O Prophet, tell your wives and your daughters and the wives of the believers to bring down over themselves [part] of their outer garments. That is more suitable, that they will be recognized. So they will not be harmed and ever is Allah Forgiving and Merciful.” [Al-Ahzab 33:59]

يا أيها النبي قل لأزواجك وبناتك ونساء المؤمنين يدنين عليهن من جلابيبهن ذلك أدنى أن يعرفن فلا يؤذين وكان الله غفورا رحيما

Abu l-Jarud reported, that Imam Al-Baqir (a.) said about the verse: ﴾Neither a believing man or woman are entitled, to have a choice in a matter when God and His Messenger have already decided a matter.﴿ (33:36): ,,This is because the Messenger of God (s.) gave Zaid, the son of Harithah, Zainab, the daughter of Jahsh, as a wife [ … ] and as for His word ﴾O Prophet, tell your wives and your daughters and the women of the believers to bring down over themselves of their outer garments ﴿, (33:59) so the reason for its descent is, that the women used to go out to the mosque and pray behind the Messenger of God (s.) and at night they used to go out to pray for the evening and the night and the last and the morning, while the youths used to sit for them at their pathway, after which they used to harm them and they used to confront them. Then God sent down: ﴾O Prophet, tell your wives and your daughters and the wives of the believers﴿ until His word ﴾That is more suitable, that they will be recognized. So they will not be harmed and ever is Allah Forgiving and Merciful.”﴿” (33:59) [Tafsir-ul-Qumi, Volume 2, page 194 + 196]

وفي رواية أبي الجارود عن أبي جعفر عليه السلام في قوله وما كان لمؤمن ولا مؤمنة إذا قضى الله ورسوله أمرا أن يكون لهم الخيرة من أمرهم وذلك أن رسول الله صلى الله عليه وآله خطب على زيد بن حارثة زينب بنت جحش [ … ] وأما قوله يا أيها النبي قل لأزواجك وبناتك ونساء المؤمنين يدنين عليهن من جلابيبهن فإنه كان سبب نزولها أن النساء كن يخرجن إلى المسجد ويصلين خلف رسول الله صلى الله عليه وآله وإذا كان بالليل خرجن إلى صلاة المغرب والعشاء والآخرة والغداة يقعد الشبان لهن في طريقهن فيؤذونهن ويتعرضون لهن فأنزل الله يا أيها النبي قل لأزواجك وبناتك ونساء المؤمنين إلى قوله ذلك أدنى ان يعرفن فلا يؤذين وكان الله غفورا رحيما

Muhammad Baqir Al-Majlisi writes: ,,The outer garment (jilbab) is the loincloth and the upper garment and it is said: ﴾It is like the veil, with which a woman covers her head, back and chest.﴿ And the plural of it is outer garments.” [Bihar-ul-Anwar, Volume 64, page 227]

قال الشيخ محمد باقر المجلسي: والجلباب الإزار والرداء وقيل هو كالمقنعة تغطي به المرأة رأسها وظهرها وصدرها وجمعه جلابيب

Imam Zain-ul-Abidin (a.) was reported to have said: ,,Have mercy on the one, who removed the veil of shamefulness from his head, removed the outer garment of the mindfulness from his arms and incurred Your wrath by committing the shameful deed. O You, Who continually forgive and pardon, have mercy on him who continually stumbles and falls.” [Bihar-ul-Anwar, Volume 91, page 158, Hadith 22]

روي عن علي زين العابدين عليه السلام أنه قال: ارحم من ألقى عن رأسه قناع الحياء وحسر عن ذراعيه جلباب الأتقياء واجترأ على سخطك بارتكاب الفحشاء فيا من لم يزل عفوا غفارا ارحم لمن لم يزل مسقطا عثارا