Hebrews 10:29 → Exodus 24:8

At Sinai, Moses "took the blood, sprinkled it on the people, and said, 'This is the blood of the covenant (dam ha-berit / LXX to haima tēs diathēkēs) that the LORD has made with you'" (Exod 24:8) — the sacrificial blood that ratified the covenant bond and consecrated Israel to Yahweh as His people. Hebrews 10:29 takes up that singular formula ("the blood of the covenant," the only OT source of the phrase, which the same author had already quoted directly — with a citation frame — at Heb 9:20) and relocates it Christologically: the apostate has "profaned the blood of the covenant that sanctified him." This is an allusion rather than a formal citation — the author does not introduce it "as it is written" but activates the established covenant-blood formula and applies it to Christ's own blood. The method is typological with a contrast-driven a fortiori engine: the type (covenant-blood that consecrates a people) corresponds and historically escalates — animal blood sprinkled on bodies at Sinai becomes the Mediator's own blood that "sanctified" the person inwardly (cf. 9:14; 10:10) — while the rhetoric runs lesser-to-greater (vv. 28-29): if despising Moses's covenant brought death without mercy, "how much worse punishment" for trampling the Son and profaning His covenant-blood. This is Contrast, not bare promise-fulfillment, because no promise is quoted; the argument turns on the disproportion of consequences between the two covenants the same blood-formula spans. The telos: the warning is severe precisely because the blood it names is supremely precious — the dread of profaning it is the shadow side of the treasure, for this is the blood that does what Sinai's blood could only signify, actually sanctifying the conscience and binding the redeemed to a Mediator worth dying not to lose. To see the blood of the covenant rightly is to find Christ so desirable that turning back from Him is unthinkable.