Deuteronomy 30; Psalm 119:73–96; Isaiah 57; Matthew 5
the paragraph matthew 5:17–20 begins the body of the Sermon on the Mount. It is a complex but enormously evocative section.
Jesus says, “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them” (5:17). These lines have called forth some popular but doubtful interpretations. (a) Some think that the verb “fulfill” must mean the opposite of “abolish,” since the last clause demands an obvious opposition (“not … to abolish … but to fulfill”). So they take Jesus to mean, “I have not come to abolish the Law but to maintain it or preserve or keep it.” But does Jesus really see his mission in such terms, especially if the maintaining or keeping of the Law is understood simply in terms of its demands and prescriptions? Even in some of the antitheses that follow (5:21–48), does it not sound as if Jesus is introducing at least some modifications? Does not Jesus introduce some changes to the food laws in Matthew 15:1–20 (cf. Mark 7:1–23)? (b) Some therefore argue that Jesus has only the moral law in mind. But it is far from clear that first-century Christians distinguished moral from civil and ceremonial law as readily as we do. In any case, 5:18 (“not the smallest letter, not the least stroke of a pen”) sounds too comprehensive to allow such a restriction. (c) Still others want “to fulfill” to mean something like “to intensify” or even “to show the true meaning of.” But the verb never carries that meaning.
The most common meaning of the verb “to fulfill” in the New Testament has to do with eschatology. In the past God predicted something; now he “fulfills” his word; he brings to pass what he promised. That is always what Matthew means by the verb (which he uses frequently). So here Jesus says, in effect, that he has not come to abolish the Law, but to do something quite different: to bring to pass all that the Law predicted. Such fulfillment will go on until everything predicted by the Law is accomplished, to the very end of the age (5:18). All of this presupposes (a) that the Law has a predictive function (a commonplace in the New Testament); (b) that Jesus does show the true meaning of the Law and Prophets, not in some abstract sense, but in their prophetic fulfillment, the true direction in which they point; and (c) that Jesus interprets his own mission as prophetic fulfillment of the promises inherent in the Law and the Prophets. He thinks of himself neither as someone who destroys all that has come before and starts over, nor as someone who simply maintains the antecedent tradition. Rather, all previous revelation points to him, and he brings its expectations to pass.
 Carson, D. A. (1998). For the love of God: a daily companion for discovering the riches of God’s Word. (Vol. 2, p. 25). Wheaton, IL: Crossway Books.