13. As recorded at Isaiah 4:3, how does Isaiah describe the remnant that would be shown mercy by Jehovah?

¹³ We have already been introduced to the remnant that would be shown mercy by Jehovah, but now Isaiah describes them in more detail. He writes: “It must occur that the ones remaining in Zion and the ones left over in Jerusalem will be said to be holy to him, everyone written down for life in Jerusalem.”​—Isaiah 4:3.

15. (a) The expression “written down for life in Jerusalem” reminds us of what Jewish custom? (b) What sobering warning do Isaiah’s words imply?

¹⁵ Will this faithful remnant remain there? They will be “written down for life in Jerusalem,” promises Isaiah. This reminds us of the Jewish custom of keeping careful registers of Israel’s families and tribes. (Nehemiah 7:5) To be written in a register meant to be alive, for when a person died, his name was removed. In other parts of the Bible, we read of a figurative register, or book, containing the names of those whom Jehovah rewards with life. But this book receives names conditionally, for Jehovah can ‘wipe out’ names. (Exodus 32:32, 33; Psalm 69:28) Isaiah’s words, then, imply a sobering warning​—the returnees may continue living in their restored land only if they remain holy in God’s sight.

17. Whose names does Jehovah write in his “book of life,” and what should we be determined to do?

¹⁷ Recall that Jehovah noted those in Israel who were holy and that he ‘wrote down their names for life.’ Today, too, Jehovah notices our endeavors to be clean in mind and body as we ‘present our bodies a sacrifice living, holy, acceptable to God.’ (Romans 12:1) And all who follow such a life course are recorded by God in his “book of life”​—the figurative record containing the names of those who are in line to receive everlasting life, either in heaven or on earth. (Philippians 4:3; Malachi 3:16) Let us, then, do our utmost to remain holy in God’s eyes, for then we may keep our names in that precious “book.”​—Revelation 3:5.