27 Esaias also crieth concerning Israel, Though the number of the children of Israel be as the sand of the sea, a remnant shall be saved: 28 For he will finish the work, and cut it short in righteousness: because a short work will the Lord make upon the earth. 29 And as Esaias said before, Except the Lord of Sabaoth had left us a seed, we had been as Sodoma, and been made like unto Gomorrha. (Romans 9:27-29 KJV)
William Burkitt’s Commentary
Here Apostle Paul shows how the reduction of the obdurate Jews was foretold by Isaiah as well as Hosea: That although the number of the Jews, according to the flesh, was as the sand of the sea, yet the greatest number of them would be passed by for their unbelief and a remnant only saved. This the prophet speaks of those Jews who escaped into the hand of Sennacherib; and the apostle makes the deliverance of those few, a type of them that should believe in Christ and be saved by him.
And the prophet further adds, That God would finish his work, and cut it short in righteousness; that is, God will make quick work with that incorrigible and unreclaimable people; such swift destruction shall come upon the multitude of evil-doers in the land of Israel as shall bring them very low, cut them short, lop them off so that they shall be left as a tree, of which only the stump remains. They shall be reduced to a small remnant and a remnant only of that remnant shall be converted.
Now first, from the literal import of those words, Though Israel be as the sand of the sea, a remnant only shall be saved, we learn, That numerous people or nations among whom God has been truly worshipped, and this for a long season, may, notwithstanding, for their wickedness be destroyed and reduced by God to a very small number.
Secondly, from the typical import of these words, together with the apostle’s scope in citing of them, we gather, that amongst those multitudes who are called by the gospel to believe in our Lord Jesus Christ, and who make profession of his name and truth, the number of those who will be at last eternally saved will be but comparatively small and little; A remnant shall be saved.