John 15:1 → Jeremiah 2:21

Jesus' self-identification as "the true vine" (hē ampelos hē alēthinē) in John 15:1 is most fully understood in contrast to the OT vine imagery for Israel, especially Jer 2:21 where God laments planting Israel as "a choice vine" (śōrēq) "from the very best seed" (זֶרַע אֱמֶת, zeraʿ ʾemet, "seed of truth/faithfulness"), only to find it turned into "a rotten, wild vine." The adjective alēthinos ("true") functions not merely as "genuine" in the abstract sense but specifically as the fulfillment-counterpart to the false, degenerate vine Israel proved to be. Where Israel-as-vine failed to produce the fruit the divine vinedresser sought (cf. Isa 5:1-7; Jer 2:21; Ezek 15; Ps 80), Jesus as the true vine succeeds — and his disciples are incorporated into him as branches that bear fruit precisely because he is not the failing vine Israel was. The escalation is Christological: the vine is no longer a metaphor for a nation but a person, and membership in the vine requires union with Jesus rather than ethnic descent.