A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
isa 4:2(Isa 4:1-6)
In contrast to those on whom vengeance falls, there is a manifestation of Jesus Christ to the "escaped of Israel" in His characteristic attributes, beauty and glory, typified in Aaron's garments (Exo 28:2). Their sanctification is promised as the fruit of their being "written" in the book of life by sovereign love (Isa 4:3); the means of it are the "spirit of judgment" and that of "burning" (Isa 4:4). Their "defense" by the special presence of Jesus Christ is promised (Isa 4:5-6).
branch--the sprout of JEHOVAH. Messiah (Jer 23:5; Jer 33:15; Zac 3:8; Zac 6:12; Luk 1:78, Margin). The parallel clause does not, as MAURER objects, oppose this; for "fruit of the earth" answers to "branch"; He shall not be a dry, but a fruit-bearing branch (Isa 27:6; Eze 34:23-27). He is "of the earth" in His birth and death, while He is also "of the Lord" (Jehovah) (Joh 12:24). His name, "the Branch," chiefly regards His descent from David, when the family was low and reduced (Luk 2:4, Luk 2:7, Luk 2:24); a sprout with more than David's glory, springing as from a decayed tree (Isa 11:1; Isa 53:2; Rev 22:16).
excellent-- (Heb 1:4; Heb 8:6).
comely-- (Sol 5:15-16; Eze 16:14).
escaped of Israel--the elect remnant (Rom 11:5); (1) in the return from Babylon; (2) in the escape from Jerusalem's destruction under Titus; (3) in the still future assault on Jerusalem, and deliverance of "the third part"; events mutually analogous, like concentric circles (Zac 12:2-10; Zac 13:8-9, &c.; Zac 14:2; Eze 39:23-29; Joel 3:1-21).
isa 4:3left in Zion--equivalent to the "escaped of Israel" (Isa 4:2).
shall be called--shall be (Isa 9:6).
holy-- (Isa 52:1; Isa 60:21; Rev 21:27).
written--in the book of life, antitypically (Phi 4:3; Rev 3:5; Rev 17:8). Primarily, in the register kept of Israel's families and tribes.
living--not "blotted out" from the registry, as dead; but written there as among the "escaped of Israel" (Dan 12:1; Eze 13:9). To the elect of Israel, rather than the saved in general, the special reference is here (Joe 3:17).
isa 4:4When--that is, After.
washed-- (Zac 13:1).
filth--moral (Isa 1:21-25).
daughters of Zion--same as in Isa 3:16.
purged--purified by judgments; destroying the ungodly, correcting and refining the godly.
blood-- (Isa 1:15).
spirit--Whatever God does in the universe, He does by His Spirit, "without the hand" of man (Job 34:20; Psa 104:30). Here He is represented using His power as Judge.
burning-- (Mat 3:11-12). The same Holy Ghost, who sanctifies believers by the fire of affliction (Mal 3:2-3), dooms unbelievers to the fire of perdition (Co1 3:13-15).
isa 4:5create--The "new creation" needs as much God's creative omnipotence, as the material creation (Co2 4:6; Eph 2:10). So it shall be in the case of the Holy Jerusalem to come (Isa 65:17-18).
upon--The pillar of cloud stood over the tabernacle, as symbol of God's favor and presence (Exo 13:21-22; Psa 91:1). Both on individual families ("every dwelling") and on the general sacred "assemblies" (Lev 23:2). The "cloud" became a "fire" by night in order to be seen by the Lord's people.
upon all the glory--"upon the glorious whole"; namely, the Lord's people and sanctuary [MAURER]. May it not mean, "Upon whatever the glory (the Shekinah spoken of in the previous clause) shall rest, there shall be a defense." The symbol of His presence shall ensure also safety. So it was to Israel against the Egyptians at the Red Sea (Exo 14:19-20). So it shall be to literal Jerusalem hereafter (Zac 2:5). Also to the Church, the spiritual "Zion" (Isa 32:18; Isa 33:15-17; Heb 12:22).
tabernacle--Christ's body (Joh 1:14). "The word 'tabernacled' (Greek for 'dwelt') among us" (Joh 2:21; Heb 8:2). It is a "shadow from the heat" and "refuge from the storm" of divine wrath against man's sins (Isa 25:4). Heat and storms are violent in the East; so that a portable tent is a needful part of a traveller's outfit. Such shall be God's wrath hereafter, from which the "escaped of Israel" shall be sheltered by Jesus Christ (Isa 26:20-21; Isa 32:2).
covert--answering to "defense" (Isa 4:5). The Hebrew for defense in Isa 4:5, is "covering"; the lid of the ark or mercy seat was named from the same Hebrew word, caphar; the propitiatory; for it, being sprinkled with blood by the high priest once a year, on the day of atonement, covered the people typically from wrath. Jesus Christ is the true Mercy Seat, on whom the Shekinah rested, the propitiatory, or atonement, beneath whom the law is kept, as it was literally within the ark, and man is covered from the storm. The redeemed Israel shall also be, by union with Him, a tabernacle for God's glory, which, unlike that in the wilderness, shall not be taken down (Isa 38:20).
A new prophecy; entire in itself. Probably delivered about the same time as the second and third chapters, in Uzziah's reign. Compare Isa 5:15-16 with Isa 2:17; and Isa 5:1 with Isa 3:14. However, the close of the chapter alludes generally to the still distant invasion of Assyrians in a later reign (compare Isa 5:26 with Isa 7:18; and Isa 5:25 with Isa 9:12). When the time drew nigh, according to the ordinary prophetic usage, he handles the details more particularly (Isa. 7:1-8:22); namely, the calamities caused by the Syro-Israelitish invasion, and subsequently by the Assyrians whom Ahaz had invited to his help.