Adv Marc IV.1.5 - 6 and Irenaeus (Strong Proof Tertullian's Adversus Marcionem Comes from Irenaeus's Adversus Marcionem)

	Tertullian — Adversus Marcionem IV.1.5–6 Irenaeus — Adversus Haereses IV.33.14 Irenaeus — Demonstratio Apostolica 89 Scriptural Sequence Jeremiah 31 (new covenant) → Isaiah 43 (new things) Jeremiah 31 → Isaiah 43 Isaiah 43 embedded within new-covenant framework Jeremiah 31 — New Covenant citation Ecce venient dies, dicit dominus, et perficiam domui Iacob et domui Iudae testamentum novum, non secundum testamentum quod disposui patribus eorum in die qua arripui dispositionem eorum ad educendos eos de terra Aegypti. “God would make a new covenant… not such as that which He made with the fathers at Mount Horeb…” New covenant theology presupposed; renewal beyond Mosaic legislation Immediate transition marker Et alibi — second prophecy introduced immediately after Jeremiah “and again…” — explicit sequential linkage Same interpretive movement from covenant renewal to Isaianic prophecy Isaiah 43 — New things citation Ne rememineritis priorum… vetera transierunt… ecce facio nova… “Remember ye not the things of old: behold I make new things… I will make a way in the desert…” “Remember not the former things… behold I make new things which shall now spring up…” Expanded citation context Shortened formulation but same conceptual structure Full expansion including desert/river imagery and theological exposition Same Isaianic interpretation tied to faith and new life Exegetical Purpose Creator predicted renewal; anti-Marcionite proof of continuity New covenant foretold by Creator; unity of salvation history Law fulfilled; believers live in newness Hermeneutical Structure Prophetic catena establishing renewal from Creator Identical prophetic catena Same Isaianic reading embedded in same argument Key Conceptual Link Renewal originates from Creator, not alien deity Renewal = liberty of new covenant Renewal = life through faith and love Distinctive Feature Same two OT texts used consecutively at programmatic opening of Book IV Same pairing and order Same Isaianic component integrated into identical theological framework What is striking in the comparison between Adversus Marcionem IV.1.5–6 and Irenaeus (Adversus Haereses IV.33.14; Demonstratio Apostolica 89) is not merely the reuse of familiar prophetic prooftexts but the preservation of a specific structural pattern: Jeremiah 31 (new covenant) immediately followed by Isaiah 43 (new things). In all three witnesses the sequence functions as a tightly linked prophetic catena designed to demonstrate that the renewal proclaimed in Christ was foretold by the Creator Himself. The structure is identical. First comes Jeremiah’s promise of a “new covenant… not like that made with the fathers,” establishing continuity of salvation history within the Creator’s plan. Immediately thereafter, introduced by a transition marker (“et alibi” in Tertullian; “and again” in Irenaeus), Isaiah 43 is cited: “Remember not the former things… behold I make new things.” This second citation provides the interpretive climax, reframing Christian novelty as prophetic fulfillment rather than rupture. The fact that the same two passages appear consecutively, joined by the same rhetorical bridge and deployed for the same theological conclusion, suggests the reuse of a pre-formed exegetical unit rather than independent selection. This pattern matters because prophetic testimonia were not randomly assembled; they were typically transmitted as stable catenae within anti-heretical argumentation. The Jeremiah 31 → Isaiah 43 pairing behaves precisely like such a fixed dossier. In Irenaeus the sequence undergirds the claim that the new covenant and the “new things” of Isaiah belong to the Creator and therefore refute dualist interpretations. Tertullian reproduces the same pairing at the programmatic opening of his Lukan commentary in Book IV, with minimal variation in structure or function. The probability that two authors independently assembled the same consecutive prooftexts, connected by the same transition formula and serving the same anti-Marcionite polemical purpose, is comparatively low. Instead, the evidence points toward literary dependence: Tertullian appears to inherit an already established prophetic catena, most plausibly deriving from Irenaeus’s anti-Marcionite tradition — perhaps even from the lost Adversus Marcionem that Irenaeus himself announces elsewhere. In this light, the Jeremiah 31 + Isaiah 43 sequence functions as a fingerprint of transmission, revealing how Tertullian’s work preserves the structural scaffolding of an earlier Irenaean argument.