Matthew 27:66

Οἱ δὲ πορευθέντες ἠσφαλίσαντο τὸν τάφον, σφραγίσαντες τὸν λίθον, μετὰ τῆς κουστωδίας.

RBT Greek Interlinear:

Strongs 3588; hoi; οἱ; the; Art-NMP

Strongs 1161; de; δὲ; and; Conj

Strongs 4198; poreuthentes; πορευθέντες; those who have led across; V-APP-NMP

Strongs 805; ēsphalisanto; ἠσφαλίσαντο; they fortified; V-AIM-3P

Strongs 3588; ton; τὸν; the; Art-AMS

Strongs 5028; taphon; τάφον; tomb; N-AMS

Strongs 4972; sphragisantes; σφραγίσαντες; those who have set a seal; V-APA-NMP

Strongs 3588; ton; τὸν; the; Art-AMS

Strongs 3037; lithon; λίθον; stone; N-AMS

Strongs 3326; meta; μετὰ; in company with; Prep

Strongs 3588; tēs; τῆς; the; Art-GFS

Strongs 2892; koustōdias; κουστωδίας; custodia; N-GFS

RBT Translation:

And the ones who have led across, they fortified the Burial Grave, those who set a signet-seal upon the Stone in company with the Custodia.

"Sealed with Blood"

σφρᾱγίζω (sphragizó) primarily means "to close or enclose with a seal." This includes sealing documents or containers to secure their contents (e.g., Euripides' Iphigenia in Aulis 38, LXX Bel. 14), authenticating documents (e.g., IG 9(1).61.78,95), certifying objects after inspection (e.g., PRev.Laws 25.10, Wilcken Chr. 89.5), and indicating pledging (e.g., Plutarch, Pompey 5). It can also refer to making an impression with a seal for various purposes (e.g., Aristotle, Memorabilia 450a32).

LITV Translation:
And going along with the guard, they made the grave secure, sealing the stone.

ESV Translation:
So they went and made the tomb secure by sealing the stone and setting a guard.