When the Lord has washed away the filth of the daughters of Zion and cleansed the bloodstains from the heart of Jerusalem by a spirit of judgment and a spirit of fire. 

Then the LORD will create over all of Mount Zion and over her assemblies a cloud of smoke by day and a glowing flame of fire by night. For overall the glory, there will be a canopy (Isaiah 4:4–5, BSB)

A life in Christ is a life of restfulness. Where the Lord Jesus Christ is the sole superintendent over the process of sanctification of the Believer. He does this by bringing the Believer to a position where his object of hope for life is the Lord alone. Where He unites the Believer’s weakness to His strength, his ignorance to His wisdom, and his frailty to His enduring might. So we do not look to ourselves, and not let the mind dwell upon ourselves, but to Christ.

Our mind dwells upon His love, upon His beauty, perfection, and character. Upon His self-denial, His humiliation, His purity and Holiness, and in His matchless love. It is by loving Him, learning of Him, and depending wholly on Him, that we are transformed into His likeness. 

In Isaiah chapter 4, verses 4 and 5, the prophet speaks of a pivotal turn of the sinful, arrogant society, specifically the daughters of Zion, to a future purification, restoration, and divine protection. This verse describes a remnant of Believers who are sanctified by God and sheltered under His presence. 

The will of God is to purify, restore, and glorify His creation, which is not bound by geography, country, tribe, or language. His will knows no bounds; therefore, when the Lord has washed and cleansed the filth and bloodstains, then the Lord will create His glory over Mount Zion and over all her assemblies.