Verse 20: And Samuel said unto the people, Fear not: ye have done all this wickedness: yet turn not aside from following the LORD, but serve the LORD with all your heart…
[Fear ye not] Namely, with a servile fear (Mendoza). They were shocked by the sudden tempest, fearing that something similar might befall them, as befell those kings, Joshua 10. But God does not suffer them to despair (Martyr). Nevertheless, do not draw back; that is to say, although your sin is grievous, He regards you in mercy, only turn not yourselves from Him any longer (Malvenda out of Junius).
Fear not, to wit, with a servile and desponding fear, as if there were no hope left for you.
Verse 21: And (Deut. 11:16) turn ye not aside: (Jer. 16:19; Hab. 2:18; 1 Cor. 8:4) for then should ye go after vain things, which cannot profit nor deliver; for they are vain.
[And do not turn aside after vain things, which shall not benefit you, and shall destroy you, because they are vain (similarly Montanus, Syriac, Arabic, Strigelius), or they are nothing (Septuagint, Jonathan),וְלֹ֖א תָּס֑וּרוּ כִּ֣י׀ אַחֲרֵ֣י הַתֹּ֗הוּ אֲשֶׁ֧ר לֹֽא־יוֹעִ֛ילוּ וְלֹ֥א יַצִּ֖ילוּ כִּי־תֹ֥הוּ הֵֽמָּה׃] The particle כִּי/for/because here creates confusion (Drusius). Verbatim: And turn not aside, because after vanity, which does not profit nor deliver; for they are vanity (Vatablus). Ye shall not turn aside after idols, which shall not profit nor deliver, because they are idols (Pagnine). Or thus: Turn not aside on any account after idols; or, turn not aside after idols, because they do not profit, etc., so that the words are transposed, but the order and construction are as I have said (Drusius). Turn not back, I say, especially after vain things, etc. (Tigurinus). Turn not aside, or back (understanding, from the Lord [Vatablus, Drusius, Dutch]), otherwise, or because then (understanding, ye should turn back, or aside [Junius, Piscator, Vatablus], or ye should follow [Dutch], or go [English, Glassius]) after vanity, or emptiness, or vain things (that is, ye should follow idols, or vain gods [Vatablus]), which do not profit nor deliver, because they are emptiness, or vanity (Junius and Tremellius, Vatablus, Munster, Dutch, English). The manner of expression is concise; many things are to be supplied. Turn not aside after idols, since those going after them go after vanity (Mariana). Do not turn aside after vanity: for these are things which do not profit, so that the order of expressions is inverted (certain interpreters in Vatablus). The sense is, if ye turn back from the Lord, nothings remains for you except to worship strange gods, which are not able to help you in anything, since they are תֺּהוּ, that is, nothing, having no power, or ability (Munster). Verily idols are vain, indeed, nothing, 1 Corinthians 8:4. They are nothing, not indeed materially, but formally, or in representation; for it represents neither truly, nor a true thing (Tirinus). They have nothing divine in them, neither are they advantageous, etc. (Dutch). Gods vain and false, in which there is no true divinity (Malvenda). תֺּהוּ is vanity or emptiness. Of which sort are idols. For they are devoid not only of divinity, but even of all good (Martyr).
[Because they are vain] Maimonides thinks that Magical Arts are treated, which are rightly called περίεργα/trifles, Acts 19:19; things of no profit, Jeremiah 16:19. For, even if no other evil be present, time, such a precious thing, is wasted on them (Grotius). Moreover, those words, which do not profit nor deliver, signify, which shall be especially hurtful to you, and fetch the anger and punishments of God; so also in Jeremiah 8:2, 11. For words of denial are quite frequently put in the place of contrary words of affirmation through a certain μείωσιν/diminution. Thus in Exodus 20:7, לֹ֤א יְנַקֶּה֙, He will not hold or declare him guiltless; that is, He will declare him guilty, and hence most grievously punish: in Leviticus 10:1, אֲשֶׁ֧ר לֹ֧א צִוָּ֖ה אֹתָֽם׃, which He commanded them not; that is, which He had firmly prohibited: in Numbers 21:23,וְלֹא־נָתַ֙ן סִיחֹ֣ן, and Sihon gave not, or permitted not, Israel to pass through his border; that is, he prohibited with all forced employed. Compare Deuteronomy 2:30. So also in Genesis 20:6; 31:7; Exodus 3:19. Some call this figure λιτότην/litotes/ understatement (Glassius’ “Grammar” 286).
Turn ye not aside, to wit, after idols; as they had often done before; and, notwithstanding this warning, did afterwards. Should ye go, or, should ye turn aside; which words are easily to be understood out of the foregoing branch, such ellipses being most frequent in Scripture, as Deuteronomy 1:4; 1 Kings 14:14; 2 Kings 9:27. Vain things; so idols are called, Deuteronomy 32:21; Jeremiah 2:5, and so they are, being mere nothings, 1 Corinthians 8:4, having no divinity nor power in them; no influence upon us, nor use or benefit to us. Which cannot profit nor deliver, that is, which will not only be unprofitable, but highly pernicious to you; the contrary affirmative being understood under the negative, as Exodus 20:7; Numbers 21:23; Deuteronomy 2:30.
Verse 22: For (1 Kings 6:13; Ps. 94:14) the LORD will not forsake his people (Josh. 7:9; Ps. 106:8; Jer. 14:21; Ezek. 20:9, 14) for his great name’s sake: because (Deut. 7:7, 8; 14:2; Mal. 1:2) it hath pleased the LORD to make you his people.
[And the Lord will not forsake His people] That is to say, not only will He not destroy; but He will not desert, will not take away His protection (Mendoza). He will not forsake His people, that is, in dangers (Osiander).
[Because of His great name] But why is this? Response: Either, 1. Because of the mercy of God, which is often signified by the name of God, as in Psalm 25:11 (Mendoza out of Gregory). Or, 2. Because of Christ. See Acts 4:12 (Mendoza out of Hugo). Or, 3. Because of Himself. For in the sacred books the name of God is frequently used for God Himself (Mendoza, Lapide). Or, 4. Because of His fame, which concerning His providence and beneficence towards this people is carried even to the Gentiles (Mendoza, similarly Menochius, Lapide, Martyr, Osiander, Tostatus, Vatablus and Sanchez in Mendoza). That is to say, lest concerning Him the Gentiles should begin to form an ill opinion. This argument is used by Moses, Exodus 32:12; Numbers 14:13; by Joshua, Joshua 7:8, 9; and by David, Psalm 79:9, 10; 113:2 (Mendoza). Lest, if the people of God should perish, His name be blasphemed among the nations and enemies, as if He were not able to deliver His people (Osiander). Because of His name, etc. But why does he not say, because of the repentance of the people? I believe, so that the people might not grow proud, and arrogate to their behavior what ought to have been attributed to divine mercy. Thus in 2 Kings 19:34, I will save it for mine own sake, etc. But why does He not say, because of Hezekiah and Isaiah? Glycas most aptly, Chronicle 2, cited in the Glossa: These words were divinely set forth, lest Hezekiah should think that his prayer ought to be heard because of the righteousness with which he was provided. Which he could also say concerning Isaiah; for, the holier he was, the more it was needful for him to be taken back from the opinion of his own holiness (Mendoza). [Those that repeatedly harp on the merits of the saints, let them weigh these words carefully; and learn what a great difference there is, between the sober flections of the commentator, who does what he does, so that he might perceive the mind of God; and perverse reasonings, which the heat of disputation extorts from men, to whom it has been appointed θέσιν διαφυλάττειν, to defend the thesis.] When He says, because of His own name, He excludes all our merit (Martyr).
For his great name’s sake, that is, for his own honour, which would seem to suffer much among men, if he should not preserve and deliver people in eminent dangers; as if he were grown feeble, or forgetful, or inconstant, or unfaithful, or regardless of human affairs, or unkind to those who own and worship him, when all the rest of the world forsake him. Hence this argument hath been oft pleaded with God, not without good success, as Exodus 32:12; Numbers 14:13, etc. And this reason God here allegeth to take them off from all conceit of their own merit; and to assure them, that if they did truly repent of all their sins, and served God with all their heart, which is here supposed, yet even in that case their salvation would not be due to their merits, but only the effect of God’s free mercy.
[Because the Lord hath sworn to make you a people for Himself,כִּ֚י הוֹאִ֣יל יְהוָ֔ה לַעֲשׂ֥וֹת וגו״] The הוֹאִיל signifies both to swear, and to will, and to undertake. And all those signification beautifully suit the sentence (Martyr). Because it pleased the Lord (the Lord willed [Pagnine, Montanus, similarly Jonathan, Vatablus], or consented [Syriac]) to make you into a people for Himself (Junius and Tremellius, Piscator, Munster, Dutch, English, Arabic, similarly Tigurinus). That is, so that it might not be incorrectly reported among the nations, which heard that He willed to make you His own people (Vatablus). Since the Lord has fully received you to Himself for a people (Septuagint). Others thus: because He began to make you a people for Himself (Osiander, Strigelius). Because God undertook to love you, and to have, to rule, to defend, etc., you as His own people: He is not changeable, that, with you cast aside (although deserving of such punishment), He might then assume one and another people to love and to save (Osiander). Not only did God will, or swear, but He also began long ago. God gave to you a law, a land, and victories. These ought to be to you definite signs, that God will to fulfill that covenant with you, which He struck of old with Abraham (Martyr).
It hath pleased the Lord, to wit, out of his own free grace, without any desert of yours, as he saith, Deuteronomy 7:7; 9:5; and therefore he will not easily forsake you, except you thrust him away.
 Hebrew: וַיֹּ֙אמֶר שְׁמוּאֵ֤ל אֶל־הָעָם֙ אַל־תִּירָ֔אוּ אַתֶּ֣ם עֲשִׂיתֶ֔ם אֵ֥ת כָּל־הָרָעָ֖ה הַזֹּ֑את אַ֗ךְ אַל־תָּס֙וּרוּ֙ מֵאַחֲרֵ֣י יְהוָ֔ה וַעֲבַדְתֶּ֥ם אֶת־יְהוָ֖ה בְּכָל־לְבַבְכֶֽם׃  Hebrew: וְלֹ֖א תָּס֑וּרוּ כִּ֣י׀ אַחֲרֵ֣י הַתֹּ֗הוּ אֲשֶׁ֧ר לֹֽא־יוֹעִ֛ילוּ וְלֹ֥א יַצִּ֖ילוּ כִּי־תֹ֥הוּ הֵֽמָּה׃  Acts 19:19a: “Many of them also which used curious arts (τὰ περίεργα, impertinences or superfluities) brought their books together, and burned them before all men…”  Jeremiah 16:19: “O Lord, my strength, and my fortress, and my refuge in the day of affliction, the Gentiles shall come unto thee from the ends of the earth, and shall say, Surely our fathers have inherited lies, vanity, and things wherein there is no profit (וְאֵֽין־בָּ֥ם מוֹעִֽיל׃).”  Hebrew: כִּ֠י לֹֽא־יִטֹּ֤שׁ יְהוָה֙ אֶת־עַמּ֔וֹ בַּעֲב֖וּר שְׁמ֣וֹ הַגָּד֑וֹל כִּ֚י הוֹאִ֣יל יְהוָ֔ה לַעֲשׂ֥וֹת אֶתְכֶ֛ם ל֖וֹ לְעָֽם׃  Michael Glycas (twelfth century) was Byzantine historian, theologian, astronomer, and poet. He wrote a Chronicle, covering events from the creation of the world to the death of Alexios I Komnenos (1118).