Isaiah 50:5 → Psalm 40:6

Both texts render obedience through the single bodily image of the divinely opened ear. Psalm 40:6 confesses, "Sacrifice and offering You did not desire, but my ears You have opened" — Hebrew ʾoznayim kārîtā lî, "ears You have dug for Me," the organ of receptive obedience hollowed out by God so that the king can hear and do His will. Isaiah 50:5, the Third Servant Song, voices the same idiom with a different verb: "The Lord GOD has opened My ears [pataḥ-lî ʾozen], and I have not been rebellious, nor have I turned back." These are the strongest Hebrew-text siblings on the opened-ear-of-the-willing-Servant motif: in both, God Himself prepares the hearing organ, and the result is not ritual but a whole-life obedience that supersedes sacrifice (Ps 40:6-8) and endures unflinching suffering (Isa 50:6). This is a Longitudinal Theme — the willing-obedient Servant whose receptive ear is the seat of his consecration runs from the pierced-ear bondservant of Exodus 21:6, through David's psalm, into Isaiah's Servant — and the link between the two texts is one of Analogy — the Davidic speaker and the Isaianic Servant are two co-ordinate instances of one opened-ear obedience, not a type and its escalated antitype (the typological consummation belongs to Christ, whom Hebrews 10 names, not to the relation between these two OT texts). It is not Promise-Fulfillment (neither text predicts the other) and not bare Contrast (the relation is positive correspondence, not antithesis); the anti-default note is that the link is genuinely a shared motif developing across the canon rather than a single prophecy and its discharge. Hebrews 10 collects this trajectory under Christ, reading Psalm 40's opened ear — via the LXX's "a body You have prepared for Me" — as the incarnate Son's mission statement; Isaiah 50:5 supplies the Servant whose obedience that body would enact unto the cross. The deletion-test telos: the opened ear is finally desirable because it discloses a Savior whose obedience was not grim duty but delight — "I delight to do Your will, O My God" — so that beholding His glad, unrebellious hearing makes us long to have our own ears opened to the same joy.