alone was God and Lord, and that He alone was to be worshipped there. בּקרבּו is in apposition to שׁמּה, “whither thou comest, in the midst of it.” The punishment announced in Deu 31:17 corresponds most closely to the sin of the nation. For going a whoring after strange gods, the anger of the Lord would burn against them; for forsaking Him, He would forsake them; and for breaking His covenant, He would hide His face from them, i.e., withdraw His favour from them, so that they would be destroyed. לאכל היה, it (the nation) will be for devouring, i.e., will be devoured or destroyed (see Ewald, §237, c.; and on אכל in this sense, see Deu 7:16, and Num 14:9). “And many evils and troubles will befall it; and it will say in that day, Do not these evils befall me, because my God is not in the midst of me?” When the evils and troubles broke in upon the nation, the people would inquire the cause, and would find it in the fact that they were forsaken by their God; but the Lord (“but I” in Deu 31:18 forms the antithesis to “they” in Deu 31:17) would still hide His face, namely, because simply missing God is not true repentance.
verses 19-23
“And now,” sc., because what was announced in Deu 31:16-18 would take place, “write you this song.” “This” refers to the song which follows in ch. 32. Moses and Joshua were to write the song, because they were both of them to strive to prevent the apostasy of the people; and Moses, as the author, was to teach it to the children of Israel, to make them learn it, that it might be a witness for the Lord (for Me) against the children of Israel. “This” is defined still further in Deu 31:20, Deu 31:21 : if Israel, through growing satisfied and fat in its land, which was so rich in costly good, should turn to other gods, and the Lord should visit it in consequence with grievous evils and troubles, the song was to answer before Israel as a witness; i.e., not only serve the Lord as a witness to the people that He had foretold all the evil consequences of apostasy, and had given Israel proper warning (Knobel), but to serve, as we may see from Deu 31:20, Deu 31:21, and from the contents of the song, as a witness, on the one hand, that the Lord had conferred upon the people so many benefits and bestowed upon them such abundant blessings of His grace, that apostasy from Him was the basest ingratitude, for which they would justly be punished; and, on the other hand, that the Lord had not rejected His people in spite of the punishments inflicted upon them, but would once more have compassion upon them and requite their foes, and thus would sanctify and glorify Himself as the only true God by His judgments upon Israel and the nations.
