Albert Barnes Commentary Malachi 3:16

"Then they that feared Jehovah spake one with another; and Jehovah hearkened, and heard, and a book of remembrance was written before him, for them that feared Jehovah, and that thought upon his name." — Malachi 3:16 (ASV)

Then those who feared the Lord spoke often among themselves - The proud-speaking of the ungodly called out the piety of the God-fearing. “The more the ungodly spoke against God, the more these spoke among themselves for God.” Both went on until the Great Day of severance. True, as those said, the distinction between righteous and wicked was not made yet, but it was stored up out of sight. They “spoke among themselves,” strengthening each other against the ungodly sayings of the ungodly.

And the Lord listened and heard it - God, whom these thought an idle looker-on, or regardless, all the while (to speak after the manner of men) was “bending the ear” from heaven “and heard.” Not one pious loyal word for Him and His glory, escaped Him.

And a book of remembrance was written before Him - Kings had their chronicles written in which people’s good or ill deeds toward them were recorded. But the image is one of the oldest in Scripture, and in the very same words, the Lord said to Moses, Write this, a memorial in a book.

God can only speak to us in our own language. One expression is not more human than another, since all are so. Since with God all things are present, and memory relates to the past, to speak of God as “remembering” is as imperfect an expression in regard to God, as to speak of “a book.”

“Forgetfulness has no place with God, because He is in no way changed; nor remembrance, because He does not forget.” Both expressions are used, only to picture vividly to our minds, that our deeds are present with God, for good or for evil; and in the Day of Judgment He will make them manifest to men and angels, as though read out of a book, and will repay them.

So Daniel had said (Daniel 7:10), the judgment was set, and the books were opened. And John says (Revelation 20:12), The books were opened, and another book was opened, which is the book of life; and the dead were judged out of those things which were written in the books, according to their works. So Moses says to God (Exodus 32:32), If not, blot me out of Your book which You have written; and David, prophesying, prays (Psalms 69:28), Let them be blotted out of the book of the living, and not be written among the righteous; and our Lord tells His disciples (Luke 10:20), Rejoice in this, that your names are written in heaven.

And those who thought upon His name - Rather, “esteemed, prized,” it, in contrast with those who (Malachi 1:6) despised; as, of Christ, when He should come, it is said (Isaiah 53:3), He was despised, and we esteemed Him not.

“The thinking on His Name signifies, not a mere thinking of, but a due esteem and reverent regard of, so as to carefully avoid all things which may tend to dishonor it, as always in His presence and with respect to Him and fear of Him.”

“Those are meant who always meditate on the ways of the Lord and the knowledge of His Godhead, for His name is Himself, and He is His Name;” “the wise in heart who know the mystery of the awesome glorious Name.”