In their Introduction to the Old Testament Dillard and Longman mention in passing an interesting passage from the Talmud about one rabbi’s view of Habakkuk 2:4.
The Talmud is a collection of rabbinical thoughts and teachings on the Jewish Scriptures. In one particular discussion (Makkot 23b–24a) several rabbis are discussing the essence of Jewish life and duty. They are searching the scriptures into order to discover the irreducible core of God’s word. What does God requires of his people?
The whole discussion is available here, but a condensed version is cited below.
One passage of the Talmud (Makkot 23b–24a) presents a delightful number game about the essence of Jewish duty.
The first move presents the opinion of Rabbi Simlai that the Torah contains 613 commandments.
Immediately we hear that King David “reduced” them to the 11 enumerated in Psalm 15: “Those who walk blamelessly, and do what is right, and speak the truth from their heart; who do not slander with their tongue, and do no evil to their friends, nor take up a reproach against their neighbors; in whose eyes the wicked are despised, but who honor those who fear the LORD; who stand by their oath even to their hurt; who do not lend money at interest, and do not take a bribe against the innocent.”
There then follows the suggestion that Isaiah reduced them to six commandments: “one who walks in righteousness, and speaks uprightly, who despises gain gotten by oppression, who refuses to take bribes, who will not listen to murderous talk, and refuses to look complacently on evil.” (Isaiah 33:15)
The challenge being clear, other suggestions quickly follow. Micah reduced them to three: “do justice, and to love kindness, and to walk humbly with your God” (Micah 6:8).
Isaiah reduced them even further to two: “Maintain justice, and do what is right” (Isaiah 56:1).
But Amos reduced them to one: “Seek me and live!” (Amos 5:4).
Rabbi Nachman ben Isaac found this too inclusive for an epitome and suggested instead: “The righteous shall live by his faith” (Habakkuk 2:4).
This discussion took place in the 4th century AD. That means the gospel of Jesus Christ had been proclaimed throughout the world for a few centuries by the time this conversation took place.
We acknowledge that what they were doing was admirable and noble. And we can agree that they were even pointed in the right direction. But we must ask if they ever reached the final destination.
They were getting close, but they fell short.
They were seeking fewer commandments, but they were still seeking commandments.
They were seeking mitzvah, not mashiach; a command, not the Christ.
As one former lawyer and Pharisee said: They had a zeal for God, but not according to knowledge. For, being ignorant of the righteousness of God, and seeking to establish their own, they did not submit to God’s righteousness. For Christ is the end of the law for righteousness to everyone who believes. (Romans 10:2-4)
I cannot help but wonder what might have happened if they had listened to that former lawyer and Pharisee centuries earlier.
According to him, the gospel was proclaimed to Abraham before the Law was given to Moses. So grace trumps works; gospel is greater than law; promise supersedes precepts.
Know then that it is those of faith who are the sons of Abraham. And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” So then, those who are of faith are blessed along with Abraham, the man of faith. For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.” Now it is evident that no one is justified before God by the law, for “The righteous shall live by faith.” But the law is not of faith, rather “The one who does them shall live by them.” Christ redeemed us from the curse of the law by becoming a curse for us—for it is written, “Cursed is everyone who is hanged on a tree”—so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith. (Galatians 3:7-14)
The rabbis started with Moses and searched for grace from the law. Paul started with Abraham and discovered grace upon grace before and beyond the law in the gospel. Why?
The law was not of faith but of works. The law was about man’s performance not God’s promise — doing not living; working not resting; achieving not receiving; cursing not blessing.
But the gospel is of faith not of works. The gospel is about God’s promise and God’s performance in Jesus Christ. It is about living not doing; resting not working; receiving not achieving; blessing not cursing.
So how can a sinner be saved?
The gospel — not the law! — is the power of God for salvation to everyone who believes. For in the gospel — not the law! — it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.” (Romans 1:16-17)
How can a sinner be justified? By faith in Christ. How can a justified sinner be sanctified? By faith in Christ. How can a sinner live and not die? By faith in Christ.
The righteousness of God is revealed from faith unto faith, not faith unto works. So whatever it takes to be justified is what it takes to be sanctified is what it takes to be glorified — faith unto faith.
There is no number of commands that can save, but there is one Christ who can. There is no combination of Christ plus commands that can save, but only condemn. Christ plus 613 commandments is not the gospel. Christ plus one commandment is not the gospel. Christ plus five steps, or plus four spiritual laws, or plus one sinner’s prayer is not the gospel.
Whether 613 commandments or eleven, six, or one commandment, the wages of the law of works is death. But the free gift of the gospel of grace is life in Christ.
Christ alone saves sinners: the blessed one became the cursed one that we cursed ones might become the blessed ones by grace alone through faith alone in Christ alone. That’s the gospel.
The gospel is good news indeed,
To sinners deep in debt;
The man who has no works to plead,
Will thankful be for it 
 Dillard, Raymond. An Introduction to the Old Testament. Grand Rapids Mich.: Zondervan, 1994. Print. p.409
 Cited in Stephen J. Einstein (ed.), Introduction to Judaism: A Source Book (Urj Press, 1999), p. 262: – See more at: http://blog.spu.edu/lectio/the-righteous-shall-live-by-his-faithfulness/#sthash.T43x2Ex3.dpuf
 William Gadsby via Red Mountain Church