וְהָ֣יוּ לִ֗י אָמַר֙ יְהוָ֣ה צְבָא֔וֹת לַיּ֕וֹם אֲשֶׁ֥ר אֲנִ֖י עֹשֶׂ֣ה סְגֻלָּ֑ה וְחָמַלְתִּ֣י עֲלֵיהֶ֔ם כַּֽאֲשֶׁר֙ יַחְמֹ֣ל אִ֔ישׁ עַל־בְּנ֖וֹ הָעֹבֵ֥ד אֹתֽוֹ׃
And they shall be Mine, saith the LORD of hosts, in the day that I do make, even Mine own treasure; and I will spare them, as a man spareth His own son that serveth him.
Read halakhic rulings (Jewish law) on Malachi 3:17: and classical halakhic sources.