“But Israel, which followed after the Law of righteousness, hath not attained to the Law of righteous-ness.”
Hoping to be justified by conforming to the Law.

“But Israel”–Meaning the Jews, who have hitherto been the people of God, though they have been industrious in observing a rule by which they supposed they could secure the blessings of God’s peculiar kingdom, yet have not come up to the true and   only rule by which those blessings can be secured.

Paul is not saying  that none of the Jews had obtained mercy, for the apostles (including Paul himself) were Jews, but that as a people, or acting according to the prevalent principles of the nation to work out their own righteousness, they had not obtained it.

“which followed after the law of righteousness”
Literally:  “following after the law of righteousness”–The phrase, “the law of righteousness,” means, the law of justice, or the just the Law, which, in their case, was the Law of  Moses.

That law demands perfect purity; and even its external observance demanded holiness. The Jews supposed that they rendered such obedience to that law as to constitute a meritorious ground of justification. This they had followed after; that is, zealously and unremittingly pursued it..  The reason  why they did not obtain justification in that way is fully stated in chapters 1-3., where it is shown that the Law demands perfect compliance with its precepts; and that Jews, as well as Gentiles, had altogether failed in rendering such compliance.

“hath not attained to the law of righteousness”
Literally:  "did not arrive at a law of righteousness"–They have not come to yield true obedience to the Law. Not such obedience that would give evidence that they have been justified. Israel attempted to keep the “letter” of the Law, but not acquittal of sin. 

         They did not arrive at that Law–it was always just out of their reach.  Why?  Because they never trusted God.  They did not come to yield true obedience to the Law, even though imperfect; that is, not such obedience as to give evidence that they have been justified.  They had the conceit of rheir self-righteousness; that is, that someday they would attain acceptance from God’s acceptance of their works.  They never gave thought of their need for God’s mercy, or of simply trusting Him.
         Thousands fail in that same attempt today.  They seek to justify themselves before God.  They attempt to weave a righteousness of their ownIsrael failed to reach legal righteousness, because to do that one had to keep perfectly all the law–“For whosoever shall keep the whole Law, and yet offend in one point, he is guilty of all”–(James 2:10).
         No conclusion could have been more humbling to a Jew than this. It constituted the whole of their prevalent religion, and was the object of their incessant toils. As they made the experiment fully, and failed; as they had the best advantages for it, and did not succeed, but reared only a miserable and delusive system of self-righteousness, (Phil. 3:4-9); it follows, that all similar experiments must fail, and that none now can be justified by the law.
         Today thousands fail in that same attempt. They seek to justify themselves before God. They attempt to weave a righteousness of their own. The moral man does this, and the immoral man attempts it as much as the moral man, and is as confident in his own righteousness. The troubled sinner does this; and this it is which keeps him so long from the cross of Christ. All this must be renounced; and man must come as a poor, lost, ruined sinner, and throw himself upon the mere mercy of God in Christ for justification and life.

“Wherefore?  Because they sought it not by faith, but as it were by the works of the Law.  Fro they stumbled at that stumblingstone”

         “Wherefore because they sought it not by faith”\\
         Literally:  “Why, because {it was} not of faith.” Is it because God eternally decreed they should not? 

Paul proceeds to state the reason why so uniform and remarkable a result (Israel being rejcted) took place.  And wherein lies their mistake?  It was their being ignorant of God’s righteousness-and His way of saving sinners by faith in Christ.  They went about striving establish their own righteousness; that is,-their own method of obtaining salvation.

         NOT BY FAITH: (Grk.–ouk ek pisteos)—Why have they not obtained justification?  Because they sought it by their own works, and as a matter of human merit; not by believing in Christ, and receiving it for His sake..  It is at this point that Paul passes from the      sovereignty of God to the responsibility of man.

“but as it were by the works of the Law”
Literally: “But as of works of law.– In effect, if not profession, but by works. They did not attend to the Abrahamic Covenant, which stands on the extensive principles of GRACE and FAITH; but they turn all their regards to the Law of Moses.  -As if salvation and     justification was attainable that way, which they iare not: Since, therefore, it is attainable only by faith, they missed it.

         They imagine that their obedience to that law gives them a right to the blessings of the Messiah's kingdom.  But, finding that the Gospel sets our special interest in God and the privileges of His Church on a different footing, they are offended, and refuse to come into it. Their attempted obedience included their prayers, fastings, sacrifices, etc., as well as compliance with the demands of the moral law. It may be asked here, perhaps, how the Jews could know any better than this? How should they know anything about justification by faith. To this it may be answered,
         That the doctrine was stated in the O.T. See Habakkuk 2:4. (Comp. 1:17. Psa. 32:1-11; 130:1-8; 14:1-7). Comp. 3:1-31; Job 9:2.  The sacrifices had reference to a future state of things, and were doubtless so understood. See the epistle to the Hebrews. The principle of justification by faith, and of living by faith had been fully brought out in the lives and experience of the saints of old (see 4:1-25; Heb. 11:1-40

“they stumbled at that stumblingstone”
Literally: “For they stumbled at the Stone of stumbling.– Justification by Faith  was a stumbling block for Israel, for it stood directly in rhe way of their religious philosophy of Justification by Works (meaning, their pwn works), and thus it became the obstacle that brought about their fall. 

      THEY STUMBLED:  (Grk.–prosekopsan)They fell; or failed; or else this was the cause of why they did not obtain it. Christ crucified was the stone of over which they stumbled..  They were offended at Christ, and opposed salvation through Him. The Jews found Christ a “a stumbling block; an offence(Grk.–skandalon)  (I Cor. 1:23).

       STUMBLINGSTONE: (Grk.–lithon prosekommatos)-Literally: a “stone of stumbling.

A stumbling-stone is a stone or impediment in the path of men, over which they will fall. Here it means that obstacle which prevented their attaining the righteousness of faith; and which was the reason for their fall, rejection, and ruin. That was the rejection and the crucifixion of their own Messiah; their unwillingness to be saved by Him; their contempt of Him and his message. For this God withheld from them the blessings of justification, and was about to cast them off as a people. This also Paul proceeds to prove was foretold by the prophets.

“As it is written, ‘Behold, I lay in Sion a stumblingstone and rock of offence:  and whosoever beleiveth on Him shall not be ashamed.’”

Two Messianic predictions are combined here, which is not unusual in quotations from the O.T.  And so combined, their prediction brings together both the classes of whom Paul is referring; those to whom Messiah should be only a stone of stumbling, and those who were to regard Him as the Cornerstone of all their hopes.

“As it is written”
Literally:  “Even as it has been written.See Isa. 8:14; 28:16. The quotation here is made up of both these passages, and contains the substance of both (Comp. also Psa.   118:22; I Pet. 2:6).   Foretold by their own prophet.

“Behold I lay in Sion”
Literally:   “Behold I place in Zion.”–Mount Zion was the hill or eminence in Jerusalem, over against Mount Moriah, on which the temple was built. On this was the palace of David, and this was the residence of the court (I Chron. 11:5-8).

I shall bring in My Messiah; but He shall be a different Person from whom the Jews expect; for, whereas they expect the Messiah to be a mighty secular prince, and to set up a secular kingdom, He shall appear  as a Man of Sorrows and acquainted with grief; and redeem mankind, not by His sword or secular power, but by His humiliation, passion, and death.  Therefore they will be offended at Him and reject Him, and think it would be a reproach to trust in such a person for salvation.

“a stumbling-stone and rock of offence”
Literally: “A Stone-of-stumbling and a Rock-of-offense.”–Something over which men shall stumble or fall. He is called a Rock of stumbling, not because it was the purpose of sending him that men   should fall, but because such would be the result.

          OFFENCE:  (Grk.–skandalon)See Matt. 5:29; 16:23.  These passages pointed out  the manner in which they would treat Christ; that the effect of believing on Him would be salvation, and of rejecting Him would be destruction. 

         An occasion of ruin to many, through their obstinate unbelief (Isa. 8:14; 28:16). Christ, the meek and lowly One, Who went about doing them good, Who healed them, loved them, and finally died for them—became to them a Stone of Stumbling.  And it was in Zion, where they had the Law, that this Stone of Stumbling was to be laid.
        The application of the term “rock” or “stone” to the Messiah is derived from the custom of building a house; as He is the Chief Cornerstone or the Immovable Foundation on which the church is to be built. It is not on human merits, but by the righteousness of the Savior that the church is to be built. (see I Pet. 2:6), “I lay in Sion a chief corner-stone.”  (Psa. 118:22), “The stone which the builders rejected is become the head stone of the corner.” (Eph. 2:20), “Jesus Christ himself being the chief corner-stone.”  This rock, designed as a corner-stone to the church, became, by the wickedness of the Jews, the block over which they fall into ruin, (I Pet. 2:8).
           Some are offended at the poverty of Christ and the meanness of His condition, others at the sublimity and sanctity of His doctrine; some are offended at His cross, others at His free grace; but some who, instead of being offended at Him, do believe on Him, shall never be ashamed of, or confounded by Him.
1.      He offended all the claims of the Jews as “children of Abraham.”
2.      He offended all their false claims of righteousness, by the light which He was—the Holy One.
3.      He offended the leaders of Israel by exposing their sin.
4.      He offended the hopes of an immediate, carnal earthly kingdom by showing that only those poor in spirit and pure of heart would be in His kingdom.
5.      He offended the nation by overthrowing its whole superstructure of works built on sandi.e., their works.    

“whosoever believeth on him”
Literally: “And everyone believing on Him.”  The “whosoever” in the KJV is not genuine or accurate and actually mars the sense of the text. Paul is quoting this passage of Scripture not to show the universality of salvation, which the word “whosoever” would suggests, but as proof  that the
Jews failed by lack of faith. 

         BELIEVETH:  (Grk.– pisteuon)This word carries the main idea.  He that believes shall not make haste to some other refuge for salvation, or what is the same, he shall not be put to shame by trusting in this Stone.

It is a humanly incurable delusion of the human heart that salvation is within the natural reach; and that at any time, if man will, ‘make up his mind like a man” and “hold out to the end”  God will accept him.  But this thought completely leaves out the word “mercy.”

“shall not be ashamed”
Literally “Will not be ashamed.”  This is taken substantially from the Septuagint translation of Isa. 28:16, though with some variation. The quotation really combines Isa. 8:4 and 28:16.
The Hebrew is, “shall not make haste” or, “flee hastily.”  The Hebrew means "shall not make haste" rather than "shall not be put to shame." In  I Pet.2:8 we have the same use of these Scriptures about Christ.

         This is the literal meaning of the Hebrew word; but it also means “to be afraid,” as one who makes haste often is; “to be agitated with fear or fright;” and hence it has a signification similar to that of shame. It expresses the substance of the same thing, i..e., failure of obtaining expected success and happiness.
        The idea here is, that the man who believes shall not be agitated, or thrown into commotion, by fear of want of success; or shall not be disappointed in his hopes; and: of course, he shall never be ashamed that he became a Christian. They who do not believe in Christ shall be agitated, fall, and sink into eternal shame and contempt, (Dan. 12:2). They who do believe shall be confident; shall not be deceived, but shall obtain the object of their desires. It is clear that Paul regarded the passage in Isaiah as referring to the Messiah. In View of this argument of Paul we may remark,
1.      That God is  Sovereign, and has a right to dispose of men as He pleases.
2.      The Doctrine of Election was displayed in the case of the Jews as an established principle of the Divine government, and is therefore true,
3.      The Doctrine of Election is a doctrine which is not arbitrary; but which will yet be seen to be wise, just, and good. It is the source of all the blessings that any mortals enjoy; and, in the case before us, it can be seen to be benevolent as well as just. It is better that God should cast off a part of the small nation of the Jews, and extend these blessings to the Gentiles, than that they should always have been confined to Jews. The world is better for it, and more good has come out of it.
4.    The fact, that the Gospel has been extended to all nations is proof that it is from heaven.
To a Jew there was no motive to attempt to break down all the existing institutions of his nation, and make the blessings of religion common to all nations, unless he knew that the gospel system was true. Yet the
apostles were Jews; educated with all the prejudices of the Jewish people.

5.     The interests of Christians are safe. They shall not be ashamed or disappointed, God will keep them, and bring them to His kingdom.
6.     Men still are offended at the cross of Christ. They codtemn and despise Him. He is to them as a root out of dry ground, and they reject Him, and fall into ruin. This is the reasonwhy sinners perish. Thus as the ancient Jews brought ruin on themselves and their country, so do sinners bring condemnation and woe on their own souls.