What is the ruling on a woman covering her face?

The Imams agreed on the obligation for a woman to cover her face when there is fear of temptation. She must always cover her face in these times due to the lack of safety from temptation and the weakness of religious deterrents. A woman's face is the most significant indicator of her beauty and incites desire. Many temptations are caused by a single glance at a woman's face. Allah (the Most High) says: (O Prophet, tell your wives and your daughters and the women of the believers to bring down over themselves [part] of their outer garments. That is more suitable that they will be known and not be abused. And ever is Allah Forgiving and Merciful).