Here the Prophet more clearly reproves and checks the impious waywardness of the people; for God, after having said that he would come and send a Redeemer, though not such as would satisfy the Jews, now claims to himself what justly belongs to him, and says that he changes not, because he is God. Under the name Jehovah, God reasons from his own nature; for he sets himself, as we have observed in our last lecture, in opposition to mortals; nor is it a wonder that God here disclaims all inconsistency, since the impostor Balaam was constrained to celebrate God's immutable constancy -- "For he is not God," he says, "who changes," or varies, "like man." (Numbers 23:19.) We now then understand the force of the words, I am Jehovah. But he adds as an explanation, I change not, or, I am not changed; for if we do not take the verb actively, the meaning is the same, -- that God continues in his purpose, and is not turned here and there like men who repent of a purpose they have formed, because what they had not thought of comes to their mind, or because they wish undone what they have performed, and seek new ways by which they may retrace their steps. God denies that anything of this kind can take place in him, for he is Jehovah, and changes not, or is not changed. The latter clause is variously explained. The verb klh, cale, means, in the first conjugation, to be consumed; but in Piel, to complete, or to make an end; and this sense would be very suitable; but a grammatical reason interferes, for it is in the first conjugation. Did grammar allow, this meaning would be appropriate, "Ye children of Israel have not made an end:" Why? "From the days of your fathers," etc.: then the verse which follows would be connected with this. But we must be content with the present reading; and a twofold view may be taken of it: the copulative "waw" may be taken as an adversative, "Though ye are not consumed, I yet am not changed:" as though it was said, "Think not that you have escaped, though I have long spared you and your sins: though then ye are not yet consumed, as I have borne with you in your great wickedness, I yet continue to be Jehovah, nor do I change my nature, and ye shall at length find that I am a just Judge; though I shall not soon execute my vengeance, punishment being held suspended, or as it were buried, yet the end will show that I am not changed." [1] But the Prophet seems rather to accuse the Jews of ingratitude in charging God with cruelty or with negligence, because he did not immediately assist them; and at the same time they did not consider within themselves that they remained alive because God had a reason derived from his own nature for sparing them, and for not rendering to them what they had deserved. The meaning then is this, "I am God, and I change not; and ought ye not to have acknowledged that wonderful forbearance through which I have spared you? for how has it been that you have not perished, and that innumerable deaths have not swallowed you up? How is it that you are yet alive? Is it because you have dealt faithfully faith me, so that it behaved me to exercise care over you? Nay, it is indeed a wonder that I had not fulminated against you so as to destroy you long ago." We hence see that he upbraids them with ingratitude for accusing him, because he did not immediately come forth in their defense: For he answers them and says, that had he been rigid and vehement in his displeasure, they could not have continued, for they had not ceased for many successive ages to seek their own ruin, as we find in what follows, for he says --

Footnotes

1 - The words may be so rendered as to allow the copulative v its ordinary meaning. The verse contains two announcements bearing on the subject in hand, -- For I am Jehovah, I have not changed; And ye are the house of Jacob, ye have not been consumed. This, I conceive, is the natural rendering of the original. God was not changed, because he was Jehovah; and they were not consumed, because they were the house of Jacob, a people in covenant with God. -- Ed.

I am the Lord, I change not - , better, more concisely, "I, the Lord
I change not - . The proper name of God, "He who Is," involves His unchangeableness. For change implies imperfection; it changes to that which is either more perfect or less perfect: to somewhat which that being, who changes, is not or has not. But God has everything in Himself perfectly. "Thou Alone, O Lord, Art what Thou Art, and Thou Art Who Art. For what is one thing in the whole and another in parts, and wherein is anything subject to change, is not altogether what Is. And what beginneth from not being, and can be conceived, as not being, and only subsisteth through another thing, returns to not-being; and what hath a 'has been,' which now is not, and a 'to be,' which as yet is not, that is not, properly and absolutely. But Thou Art what Thou Art. For whatever Thou Art in any time or "way," that Thou Art wholly and always; and Thou Art, Who Art properly and simply, because Thou hast neither 'to have been' or 'to be about to be;' but only to be present; and canst not be conceived, ever not to have been." "There is only one simple Good, and, therefore, One Alone Unchangeable, which is God."
"Our" life is a "becoming" rather than a simple "being;" it is a continual losing of what we had, and gaining what we had not, for "in as far as any one is not what he was, and is what he was not, so far forth he dieth and ariseth;" dieth to what he was, ariseth to be something otherwise.
"Increase evidences a beginning; decrease, death and destruction. And, therefore, Malachi says, 'I am God, and I change not,' ever retaining His own state of being; because what has no origin cannot be changed."
So the Psalmist says Psalm 102:27, "As a vesture, Thou shalt change them and they shall be changed, but Thou art the Same, and Thy years shall not fail;" and Balaam, controlled by God Numbers 23:19. "God is not a man, that He should lie, or the son of man, that He should repent;" and James 1:17, "with whom is no variableness, neither shadow of turning."
Of this unchangeableness of God, His holy ones partake, as far as they fix themselves on God. "The soul of man hangs upon Him, by whom it was made. And because it was made, to desire God Alone, but everything which it desires below is less than He, rightly doth not that suffice it, which is not God. Hence, is it, that the soul is scattered hither and thither, and is repelled from everything, toward which it is borne, through satiety of them. But holy men guard themselves by cautious observation, lest they should be relaxed from their intentness by change, and because they desire to be the same, wisely bind themselves to the thought, whereby they love God. For in the contemplation of the Creator, they will receive this, that they should ever enjoy one stability of mind. No changeableness then dissipates them, because their thought ever perseveres, free from unlikeness to itself. This therefore they now imitate, striving with effort, which hereafter they shall with joy receive as a gift." To which unchangeableness the prophet had bound himself by the power of love, when he said Psalm 27:4, "One thing I required of the Lord, which I will require, that I may dwell in the house of the Lord." To this unity Paul clave intently, when he said, Philippians 3:13-14 : "One thing I do, forgetting those things which are behind and stretching forth to those things which are before, I press forward toward the mark for the prize of the high calling of God in Christ Jesus."
And ye sons of Jacob are not consumed - Man would often have become weary of man's wickedness and waywardness. We are impatient at one another, readily despair of one another. God might justly have cast off them and us; but He changes not. He abides by the covenant which He made with their fathers; He consumed them not; but with His own unchangeable love awaited their repentance. Our hope is not in ourselves, but in God.

I am the Lord, I change not - The new dispensation of grace and goodness, which is now about to be introduced, is not the effect of any change in my counsels; it is, on the contrary, the fulfillment of my everlasting purposes; as is also the throwing aside of the Mosaic ritual, which was only intended to introduce the great and glorious Gospel of my Son.
And because of this ancient covenant, ye Jews are not totally consumed; but ye are now, and shall be still, preserved as a distinct people - monuments both of my justice and mercy.

For I [am] the LORD, I change not; therefore ye sons of Jacob (f) are not consumed.
(f) They murmured against God, because they did not see his help which was ever present to defend them: and therefore he accuses them of ingratitude, and shows that in that they are not daily consumed, it is a sign that he still defends them, and so his mercy towards them never changes.

For I am the Lord,.... Or Jehovah; a name peculiar to the most High, and so a proof of the deity of Christ, who here speaks; and is expressive of his being; of his self-existence; of his purity and simplicity; of his immensity and infinity; and of his eternity and sovereignty:
I change not; being the same today, yesterday, and forever; he changed not in his divine nature and personality by becoming man; he took that into union with him he had not before, but remained the same he ever was; nor did he change in his threatenings of destruction to the Jews, which came upon them according to his word; nor in his promises of his Spirit, and presence, and protection to his people; nor will he ever change in his love and affections to them; nor in the efficacy of his blood, sacrifice, and righteousness; wherefore, as this is introduced to assure the truth and certainty of what is said before, concerning his being a swift witness against the wicked, so also for the comfort of the saints, as follows. The Targum is,
"for I the Lord have not changed my covenant.''
Therefore ye sons of Jacob are not consumed; such who were Israelites indeed, true believers in Christ; these were not consumed when the wicked Jews were, but were directed to leave the city before its destruction, and go to another place, as they did, whereby they were preserved; and so it was, that not one Christian perished in it; See Gill on Matthew 24:13 and so it is owing to the unchangeable love, grace, and power of Christ, that none of his perish internally or eternally, but have everlasting life.

the Lord--Jehovah: a name implying His immutable faithfulness in fulfilling His promises: the covenant name of God to the Jews (Exodus 6:3), called here "the sons of Jacob," in reference to God's covenant with that patriarch.
I change not--Ye are mistaken in inferring that, because I have not yet executed judgment on the wicked, I am changed from what I once was, namely, a God of judgment.
therefore ye . . . are not consumed--Ye yourselves being "not consumed," as ye have long ago deserved, are a signal proof of My unchangeableness. Romans 11:29 : compare the whole chapter, in which God's mercy in store for Israel is made wholly to flow from God's unchanging faithfulness to His own covenant of love. So here, as is implied by the phrase "sons of Jacob" (Genesis 28:13; Genesis 35:12). They are spared because I am JEHOVAH, and they sons of Jacob; while I spare them, I will also punish them; and while I punish them, I will not wholly consume them. The unchangeableness of God is the sheet-anchor of the Church. The perseverance of the saints is guaranteed, not by their unchangeable love to God, but by His unchangeable love to them, and His eternal purpose and promise in Christ Jesus [MOORE]. He upbraids their ingratitude that they turn His very long-suffering (Lamentations 3:22) into a ground for skeptical denial of His coming as a Judge at all (Psalm 50:1, Psalm 50:3-4, Psalm 50:21; Ecclesiastes 8:11-12; Isaiah 57:11; Romans 2:4-10).

I change not - I have an unchangeable hatred to sin: and my long suffering also changeth not, therefore you are not consumed in your sins. Not consumed - God is the same in his wisdom to order the rewards of good and bad in the fittest season, therefore neither the one nor the other are consumed, but preserved to the season appointed of God.