Fear not. Isaiah now explains the reason why he formerly spoke of the power of God, that is, in order to confirm the faith of the people. From the preceding statements he draws this conclusion, -- "Since the Lord is so powerful, and governs all things at his pleasure, the people whom he hath taken under his protection ought not to fear." Have I not since then made thee hear? He next repeats what he had already said, that God not only brought assistance secretly to the Jews, and suddenly, as if by legerdemain, made his appearance when he was least expected, but kept their faith alive by many predictions, and, in short, gave manifest proofs of his fatherly kindness, so that his divinity was clearly perceived. It would be of no advantage to us that God knows and can do all things, if it were not also revealed how great concern he takes in our salvation. Although, therefore, he wishes that many things should be unknown to us, yet he communicates everything that is useful or advantageous for us to know. m'z, (meaz,) from then, means a long period; or, if it be thought better, it denotes an opportunity; for the Lord reveals his secrets to the elect, when he sees a fit season; but the former interpretation appears to me to be more simple. Therefore ye are my witnesses. He means what I have already remarked, that the people cannot plead the excuse of ignorance for not being satisfied with one God; for he has abundantly revealed himself to them, so as to give a testimony concerning himself. The object intended to be gained by our knowledge of the glory of God is, that we should profess his truth before men, as has been already said, if we do not wish to extinguish the light which he hath brought to us by his Spirit. Again, we cannot be "witnesses to God" if we are not confirmed by his truth; for a testimony proceeding from a doubtful opinion would be of no avail, and therefore we must be taught by the Word of God, so as to have a fixed and unhesitating hope of salvation. And there is no strong God. [1] In this passage, as in many others, he applies to God the epithet strong; for it is not enough to acknowledge God's eternal essence, if we do not also ascribe strength to him. But for this, we shall leave him nothing but a bare and empty name, as is done by wicked men, who with the mouth confess God, and afterwards ascribe his power to this and to that.

Footnotes

1 - "There is no God. Heb., Rock. -- (Eng. Ver.)

Fear ye not, neither be afraid - (see the notes at Isaiah 41:10). The word rendered here 'be afraid,' occurs nowhere else in the Bible. There can be no doubt, however, in regard to its meaning. The Septuagint renders it, Μηδέ πλανᾶσθε Mēde planasthe - 'Neither be deceived.' All the other ancient versions express the sense to fear, to be afraid (Gesenius' Lexicon on the word ירה yârahh).
Have not I told thee from that time - Have I not fully declared from the very commencement of your history as a people, in the main what shall occur?
Ye are even my witnesses - (See the notes at Isaiah 43:12).
Is there a God besides me? - This is a strong mode of affirming that there is no God besides Yahweh (see the note at Isaiah 44:6).
Yea, there is no God - Margin, 'Rock' (צור tsûr). The word rock is often applied to God (see the note at Isaiah 30:29; compare Deuteronomy 32:4, Deuteronomy 32:30-31; Psalm 19:14; Psalm 31:2-3; Psalm 42:9; et soepe al. The idea is taken from the fact that a lofty rock or fastness was inaccessible by an enemy, and that those who fled there were safe.

Fear ye not - תרהו - to tirehu never occurs. Perhaps it should be תיראו tireu, fear ye. Two MSS. read תירהו tirehu, and one of mine תהרו taharu.

Fear ye not, neither be afraid: have not I told thee from that time, and have declared [it]? (l) ye [are] even my witnesses. Is there a God besides me? verily, [there is] no God; I know not [any].
(l) Read (Isaiah 43:10).

Fear ye not, neither be afraid,.... Of the accomplishment of prophecies and promises, and of professing the true God, and of adhering to Jesus Christ, the only Redeemer and Saviour; or of the gods of the Heathens, and of persecuting tyrants, and what they can do against you, and in favour of their idolatrous religion:
have not I told thee from that time, and have declared it? what should come to pass, before it did, even everything that has since the appointment of the ancient people; and particularly what troubles and persecutions the apostles, ministers of the word, the first Christians should meet with among the Heathens, for professing and propagating the Gospel, and what success they should meet with, which came to pass accordingly:
ye are even my witnesses; as especially the apostles were, who had it from Christ's own mouth, that they should be hated and persecuted for the sake of the Gospel, and should be successful wherever they came; as they also were his witnesses in Jerusalem, and Judea, and Samaria, and unto the uttermost parts of the earth, of his person, doctrine, miracles, death, resurrection, and ascension to heaven, Acts 1:8,
is there a God besides me? that is a true God; for there were many fictitious and false deities, but none omniscient and omnipotent, that could foretell future events, and accomplish them as he did; there is no god but the one God, Father, Son, and Spirit; for this an appeal is made to the witnesses:
yea, there is no God, I know not any; or, there is "no rock" (a); or, is there any? a word used for God, Deuteronomy 32:4, there is no rock to build upon for salvation, no rock for shelter and safety, but Christ the rock of ages, on which the church is built, and the gates of hell cannot prevail against it, Matthew 16:18, and if God, who is omniscient, knows none else, there can be no other.
(a) "nulls rupes", Junius & Tremellius, Piscator; "non est petra", Montanus, Cocceius; "estne rupes?" Vitringa.

be afraid--literally, "be astounded," or "distracted with fear."
from that time--namely, from the time that "I appointed the ancient people" (Isaiah 44:7). From the time of Abraham's call, his family were the depositories of the predictions of the Redeemer, whereas the promise of Cyrus was not heard of till Isaiah's time; therefore, the event to the prediction and accomplishment of which God appeals in proof of His sole Godhead, is the redemption of man by a descendant of Abraham, in whose person "the ancient people" was first formally "appointed." The deliverance of the Jews, by Cyrus, is mentioned afterwards only as an earnest of that greater mercy [HORSLEY].
no God--Hebrew, tsur, "rock" (Deuteronomy 32:4); that is, a stronghold to take refuge in, and a solid foundation to build on.

Of course, none of the heathen gods could in any way answer to the challenge. So much the more confident might Israel be, seeing that it had quite another God. "Despair ye not, neither tremble: have not I told thee long ago, and made known, and ye are my witnesses: is there a God beside me? And nowhere a rock; I know of none." The Jewish lexicographers derive תּרהוּ (with the first syllable closed) from רהה (רה); whereas modern lexicographers prefer some of them to read תּרהוּ, tı̄rehū, from ירהּ (Ges., Knobel), and others תּיראוּ (Ewald). But the possibility of there being a verb רהה, to tremble or fear, cannot for a moment be doubted when we think of such words as ירא, ירע, compare also Arab. r'h (applied to water moving to and fro). It was not of the heathen deities that they were directed not to be afraid, as in Jeremiah 10:5, but rather the great catastrophe coming upon the nations, of which Cyrus was the instrument. In the midst of this, when one nation after another would be overthrown, and its tutelar gods would prove to be worthless, Israel would have nothing to fear, since its God, who was no dumb idol, had foretold all this, and that indeed long ago (מאז, cf., מראשׁ, Isaiah 41:26), as they themselves must bear witness. Prophecies before the captivity had foretold the conquest of Babylon by Medes and Elamites, and the deliverance of Israel from the Babylonian bondage; and even these prophecies themselves were like a spirit's voice from the far distant past, consoling the people of the captivity beforehand, and serving to support their faith. On the ground of such well-known self-manifestations, Jehovah could well ask, "Is there a God beside me?" - a virtual denial in the form of an interrogation, to which the categorical denial, "There is no rock (i.e., no ground of trust, Isaiah 26:4; Isaiah 17:10), I know of none (beside me)," is attached.

Ye - Thee, O Israel, whom he bids not to fear. Told thee - Even from the first ages of the world. Declared - Have published it to the world in my sacred records. Witnesses - Both of my predictions, and of the exact agreeableness of events to them.