56. Marcion was the first to call Matthew 5:21 - 48 'the Antitheses'

For this Marcion relied upon the antitheses of Matt. 5:21-49, indicating that this book was probably issued (or revised) in Rome.[Richard Pervo, the Making of Paul p. 351]  

Some scholars have viewed the Antitheses (in Matthew) as attacks on the law or as enunciations of Jesus nullification of at least certain aspects of the Law. R. Bultmann, Jesus and the Word, trans. L. P. Smith and E. H. Lantero (New York: Charles Scribner's Sons, 1958), 89–90; Luz, Matthew: A Commentary, 1:228–30; G. Strecker, “Die Antitheses der Bergpredigt (Mt 5:21–48 par),” ZNW 69 (1978):71. This position is most often affirmed for Matt 5:38 - 42. See W. Barclay, The Gospel of Matthew, rev. ed. (Philadelphia: Westminster John Knox, 1975), 133; Meier, Law and History, 157 (who describes Matt 5:38–42 as "the clearest and least disputable case of annulment in the antitheses) and F. Thielman, The Law and the New Testament: The Question of Continuity (New York: Crossroad, 1999), 49–60. [Charles Quarles Sermon on the Mount p. 105] 

The title “antitheses” seems to have first been used by Marcion; see Betz, Sermon on the Mount, 200. Betz argues that this last antithesis is intended to sum up the five previous antitheses; see ibid., 204–205. [Beth A. Berkowitz Assistant Professor of Talmud and Rabbinics Jewish Theological Seminary Execution and Invention p. 298]

Marcion was an early Christian theologian who was expelled from the Church for advocacy of this idea. Marcionite views, however, predate Marcion. Perhaps the earliest statement of the "heresy" may be found in Matthew 5:21-48. [New Outlook Vol 8 p. 679] 

Marcion also showed a discrepancy between the Hebrew and the Christian Bibles when he compared Exodus 21:23–25 and Matthew 5:38–45. Exodus 21:23–25 states: “If any harm follows [a crime], then you shall give life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, bruise for bruise" To Marcion, such laws were cruel and should not apply to Christians. He then compared the Exodus passage to Matthew 5:38–45, where Jesus specifically counters the law found in Exodus [Kevin Kaatz the Early Controversies and Growth of Christianity p. 50] 

With Marcion's Antitheses and Adda/Adimantus' adoption of that model, in both cases it appears that the task of problematising the status of the Jewish Bible was indicated not by any authority external to the text, but by the teachings of Jesus himself and the 'antitheses' in Mt. 5. 21-48, which indicated that the teaching of the Gospel superseded the injunctions of the Mosaic Law. Indeed, we know that Marcion's attentions were drawn to this section of the Gospel in particular; however, it is difficult to gauge the extent of the influence of this section in Matthew on Marcion's theological and literary model, with his apparent rejection of this gospel in toto in favor of Luke. Nevertheless, Marcion clearly paid close attention to this section, and he was drawn in particular to Mt. 5.17 158 the proof supplied by the Matthean antitheses indicates that Jesus did come to abolish the Law and the Prophets, although ol lovba'ioxai had tried to indicate otherwise.159 Identical concerns are evident in the exegetical work of Adimantus. Thus, beyond positing simple statements of comparison between Marcion's Antitheses and the work of Adimantus, the presence of the antithetical argument Ex. 21 . 24 v. Mt. 5. 38-40, in Adimantus' work (c. Adim. 8), together with the extensive treatment of Mt. 5. [157] Later Marcionite exegetes identified the antithetical pairing of Lk. 6. 29 and Ex. 21 . 24, as suggested by Mt. 5. 38-39; see A. von Harnack, Marcion, 280*-28 1. ls8 verse, see Tertullian, adv. Marc. IV. 7 (ed. E. Evans, 278-9); for the verse as a focus for Marcion's polemic, see adv. Marc. V. 14 (ed. E. Evans, 602-3): Dixerit Christus an non, Ego non veni legem disolvere sed implere, frustra de ista sententia neganda Pontus laboravit. Additional material concerning the heterodox reception of the vs. is provided by H. Betz, The Sermon on the Mount, 1 73-1 76. 159 See Adamantius, De recta in deum fide U. 15, cited in A. von Harnack, Marcion, 252, nt. 3 [Nicholas Baker-Brian Manichaeanism in the Later Roman Empire,  p. 56] 

Marcion's reading of the Old Testament convinced him that the principle of retributive justice found in the Old Testament could not be reconciled with that of love and goodness as represented by the God of the new cove¬nant (Tertullian, " Against Marcion," I., vi.; ANF, iii. 275). The creating God is just according to the maxim, "an eye for an eye, a tooth for a tooth"; this maxim was expressly annulled by the good God (Matt. v. 38 39). [New Schaff-Herzog Encylopedia p. 179] 

Marcion did not create his system himself. Before him, Cerdo, according to Theodoret's account (Hceret. fabulce, i. 24), proved by the Gospels that the just God of the old covenant and the good God of the new are different beings ; and he founded this contrariety on the precepts of the Sermon on the Mount (Matt. v. 38-48 ; Luke vi. 27-38). [Frédéric Louis Godet Commentary on the Gospel of St Luke p. 6]