Then those who feared the LORD spoke to one another,
    And the LORD listened and heard them;
    So a book of remembrance was written before Him
    For those who fear the LORD
    And who meditate on His name.
 “They shall be Mine,” says the LORD of hosts,
    “On the day that I make them My jewels.
    And I will spare them
    As a man spares his own son who serves him.”

The verse applies in the future to the believing Jews who return to the Lord in humble submission (Isaiah 10:21-23, Hosea 3:4–5, Hosea 5:15–6:1, Zech. 12:10 etc.). The principle of preciousness of those who believe on Jehovah applies to all, in that a believer in Jesus Christ is precious to God in His sight, having sacrificed His son to save such a person.