Charles Ellicott Commentary Isaiah 4:3

"And it shall come to pass, that he that is left in Zion, and he that remaineth in Jerusalem, shall be called holy, even every one that is written among the living in Jerusalem;" — Isaiah 4:3 (ASV)

He that is left in Zion ... — The prophet turns from the Jerusalem that existed then, with the hypocrisies and crimes of the men and the harlot fashions of its women, to the vision of a new Jerusalem, which will realize the ideal of Psalm 15 and Psalm 24. There every one should be called “holy” (compare 1 Corinthians 1:2; 2 Corinthians 1:1), and the name should be no unreal mockery (Isaiah 32:5), but should express the self-consecration and purity of its inhabitants.

Every one that is written among the living. — Literally, for life. The idea is that of “the book” or “register” of life in which are written the names of those who are worthy of living in the heavenly city. This idea is found as early as Exodus 32:32, and appears in Psalm 56:8; Psalms 69:28; Ezekiel 13:9; Malachi 3:16; Daniel 12:1; Acts 13:48; Philippians 4:3; Revelation 3:5; Revelation 13:8; Revelation 21:27. An examination of the passages, especially the first, will show that while it involves the idea of an election, it excludes that of an irreversible predestination, and that the election has to be “made sure” by a life in harmony with it (2 Peter 1:10).