Biblical Commentary on the Old Testament, by Carl Friedrich Keil and Franz Delitzsh, [1857-78], at sacred-texts.com
Nevertheless the rejection of Israel and its dispersion among the heathen were not to be the close. If the people should return to the Lord their God in their exile, He would turn His favour towards them again, and gather them again out of their dispersion, as had already been proclaimed in Deu 4:29. and Lev 26:40., where it was also observed that the extremity of their distress would bring the people to reflection and induce them to return.
"When all these words, the blessing and the curse which I have set before thee, shall come." The allusion to the blessing in this connection may be explained on the ground that Moses was surveying the future generally, in which not only a curse but a blessing also would come upon the nation, according to its attitude towards the Lord as a whole and in its several members, since even in times of the greatest apostasy on the part of the nation there would always be a holy seed which could not die out; because otherwise the nation would necessarily have been utterly and for ever rejected, whereby the promises of God would have been brought to nought, - a result which was absolutely impossible. "And thou takest to heart among all nations," etc., sc., what has befallen thee - not only the curse which presses upon thee, but also the blessing which accompanies obedience to the commands of God, - "and returnest to the Lord thy God, and hearkenest to His voice with all the heart," etc. (cf. Deu 4:29); "the Lord will turn thy captivity, and have compassion upon thee, and gather thee again." את־שׁבוּת שׁוּב does not mean to bring back the prisoners, as the more modern lexicographers erroneously suppose (the Kal שׁוּב never has the force of the Hiphil), but to turn the imprisonment, and that in a figurative sense, viz., to put an end to the distress (Job 42:10; Jer 30:8; Eze 16:53; Psa 14:7; also Psa 85:2; Psa 126:2, Psa 126:4), except that in many passages the misery of exile in which the people pined is represented as imprisonment. The passage before us is fully decisive against the meaning to bring back the prisoners, since the gathering out of the heathen is spoken of as being itself the consequence of the "turning of the captivity;" so also is Jer 29:14, where the bringing back (השׁיב) is expressly distinguished from it. But especially is this the case with Jer 30:18, where "turning the captivity of Jacob's tents" is synonymous with having mercy on his dwelling-places, and building up the city, again, so that the city lying in ruins is represented as שׁבוּת, an imprisonment.
(Note: Hupfeld (on Psa 14:7) has endeavoured to sustain the assertion that שׁבוּת is a later form for the older and simpler forms, שׁבי, שׁביה, by citing one single passage of the Old Testament. The abstract form of שׁבי is שׁבית, imprisonment (Num 21:29), then prisoners. This form has been substituted by Jeremiah for שׁבוּת in one passage, viz., Deu 32:44; and the Masoretic punctuators were the first to overlook the difference in the two words, and point them promiscuously.)
The gathering of Israel out of all the countries of the earth would then follow. Even though the rejected people should be at the end of heaven, the Lord would fetch them thence, and bring them back into the land of their fathers, and do good to the nation, and multiply them above their fathers. These last words show that the promised neither points directly to the gathering of Israel from dispersion on its ultimate conversion to Christ, nor furnishes any proof that the Jews will then be brought back to Palestine. It is true that even these words have some reference to the final redemption of Israel. This is evident from the curse of dispersion, which cannot be restricted to the Assyrian and Babylonian captivities, but includes the Roman dispersion also, in which the nation continues still; and it is still more apparent from the renewal of this promise in Jer 32:37 and other prophetic passages. But this application is to be found in the spirit, and not in the latter. For if there is to be an increase in the number of the Jews, when gathered out of their dispersion into all the world, above the number of their fathers, and therefore above the number of the Israelites in the time of Solomon and the first monarchs of the two kingdoms, Palestine will never furnish room enough for a nation multiplied like this. The multiplication promised here, so far as it falls within the Messianic age, will consist in the realization of the promise given to Abraham, that his seed should grow into nations (Gen 17:6 and Gen 17:16), i.e., in the innumerable multiplication, not of the "Israel according to the flesh," but of the "Israel according to the spirit," whose land is not restricted to the boundaries of the earthly Canaan or Palestine (see p. 144). The possession of the earthly Canaan for all time is nowhere promised to the Israelitish nation in the law (see at Deu 11:21).
The Lord will then circumcise their heart, and the heart of their children (see Deu 10:16), so that they will love Him with all their heart. When Israel should turn with true humility to the Lord, He would be found of them, - would lead them to true repentance, and sanctify them through the power of His grace, - would take away the stony heart out of their flesh, and give them a heart of flesh, a new heart and a new spirit, - so that they should truly know Him and keep His commandments (vid., Eze 11:19; Eze 36:26; Jer 31:33. and Deu 32:39.). "Because of thy life," i.e., that thou mayest live, sc., attain to true life. The fulfilment of this promise does not take place all at once. It commenced with small beginnings at the deliverance from the Babylonian exile, and in a still higher degree at the appearance of Christ in the case of all the Israelites who received Him as their Saviour. Since then it has been carried on through all ages in the conversion of individual children of Abraham to Christ; and it will be realized in the future in a still more glorious manner in the nation at large (Rom 11:25.). The words of Moses do not relate to any particular age, but comprehend all times. For Israel has never been hardened and rejected in all its members, although the mass of the nation lives under the curse even to the present day.
But after its conversion, the curses, which had hitherto rested upon it, would fall upon its enemies and haters, according to the promise in Gen 12:3.
Israel would then hearken again to the voice of the Lord and keep His commandments, and would rejoice in consequence in the richest blessing of its God. In the expression, ושׁמעתּ תשׁוּב אתּה ("thou shalt return and hearken"), תּשׁוּב ("thou shalt return") has an adverbial signification. This is evident from the corresponding expression in Deu 30:9, "for Jehovah will again rejoice over thee" (lit., "will return and rejoice"), in which the adverbial signification is placed beyond all doubt.
Deu 30:8-10 contain the general thought, that Israel would then come again into its normal relation to its God, would enter into true and perfect covenant fellowship with the Lord, and enjoy all the blessings of the covenant.
Deu 30:9 is a repetition of Deu 28:11. The Lord will rejoice again over Israel, to do them good (vid., Deu 28:63), as He had rejoiced over their fathers. The fathers are not the patriarchs alone, but all the pious ancestors of the people.
A renewed enforcement of the indispensable condition of salvation.
The fulfilment of this condition is not impossible, nor really very difficult. This natural though leads to the motive, which Moses impresses upon the hearts of the people in Deu 30:11-14, viz., that He might turn the blessing to them. God had done everything to render the observance of His commandments possible to Israel. "This commandment" (used as in Deu 6:1 to denote the whole law) is "not too wonderful for thee," i.e., is not too hard to grasp, or unintelligible (vid., Deu 17:8), nor is it too far off: it is neither in heaven, i.e., at an inaccessible height; nor beyond the sea, i.e., at an unattainable distance, at the end of the world, so that any one could say, Who is able to fetch it thence? but it is very near thee, in thy mouth and in thy heart to do it. It not only lay before the people in writing, but it was also preached to them by word of mouth, and thus brought to their knowledge, so that it had become a subject of conversation as well as of reflection and careful examination. But however near the law had thus been brought to man, sin had so estranged the human heart from the word of God, that doing and keeping the law had become invariably difficult, and in fact impossible; so that the declaration, "the word is in thy heart," only attains its full realization through the preaching of the gospel of the grace of God, and the righteousness that is by faith; and to this the Apostle Paul applies the passage in Rom 10:8.
In conclusion, Moses sums up the contents of the whole of this preaching of the law in the words, "life and good, and death and evil," as he had already done at Deu 11:26-27, in the first part of this address, to lay the people by a solemn adjuration under the obligation to be faithful to the Lord, and through this obligation to conclude the covenant afresh. He had set before them this day life and good ("good" = prosperity and salvation), as well as death and evil (רע, adversity and destruction), by commanding them to love the Lord and walk in His ways. Love is placed first, as in Deu 6:5, as being the essential principle of the fulfilment of the commandments. Expounding the law was setting before them life and death, salvation and destruction, because the law, as the word of God, was living and powerful, and proved itself in every man a power of life or of death, according to the attitude which he assumed towards it (vid., Deu 32:47). נדּח, to permit oneself to be torn away to idolatry (as in Deu 4:19).
As Deu 4:26; Deu 8:19. He calls upon heaven and earth as witnesses (Deu 30:19, as in Deu 4:26), namely, that he had set before them life and death. וּבחרתּ, in Deu 30:19, is the apodosis: "therefore choose life."
חיּיך הוּא כּי, for that (namely, to love the Lord) is thy life, that is, the condition of life, and of long life, in the promised land (vid., Deu 4:40).