NOTES for Isa 4:2-6
Here hope is given not only to the Israelites, but also to us, sinners from other times and nations. No matter how a people may be perishing, poisoned by the fumes of its own sins, the Lord gives those who refuse to immerse themselves in impurity the possibility of an entirely different life. The words that not everyone will survive sound bitter, for the possibility of life was offered to each person. But those who remain faithful to the Creator and preserve themselves from defilement will be called holy, that is, set apart from ordinary existence. And this is not a privilege, for the Lord calls to holiness everyone whom He has called to follow Him.
In the prophetic vision, Jerusalem ceases to be an earthly city and becomes the image of an entirely different life, inseparable from its Source. The faithful remnant will become the seed of a new humanity, redeemed and freed from the power of evil and sin, a pledge of the world's transfiguration.