Matthew 27:66σφραγίσαντες
So they went and secured the tomb by sealing the stone and posting the guard.
John 3:33ἐσφράγισεν
Whoever accepts His testimony has certified that God is truthful.
Romans 15:28σφραγισάμενος
So after I have completed this service and have safely delivered this bounty to them, I will set off to Spain by way of you.
2 Corinthians 1:22σφραγισάμενος
placed His seal on us, and put His Spirit in our hearts as a pledge of what is to come.
Ephesians 1:13ἐσφραγίσθητε
And in Him, having heard and believed the word of truth—the gospel of your salvation—you were sealed with the promised Holy Spirit,
Revelation 7:4ἐσφραγισμένων
And I heard the number of those who were sealed, 144,000 from all the tribes of Israel:

Abbott-Smith

σφραγίζω
[in LXX chiefly for חָתַם (Deu.32:34, al.), also for סָתַם (Da TH Dan.8:26) ;]
to seal,

(a) for security: Mat.27:66, Rev.20:3; τ. καρπὸν τοῦτον, figuratively (cf. Deiss., BS, 238 f.; MM, xxiv; DB, iv, 427a), Rom.15:28;

(b) for concealment, hence, metaphorically, to hide (Da TH Dan.9:24, Jhn.14:17): Rev.10:4 22:10;

(with) for distinction, Rev.7:3-8; metaphorically, Eph.4:30; mid., 2Co.1:22;

(d) for authentication (Est.8:8): Jhn.3:33 6:27 (cf. κατα-σφραγίζω).†
(AS)

Sources: Abbott-Smith’s Manual Greek Lexicon of the New Testament (1922, public domain) and glosses from STEPBible TBESG (CC BY 4.0); STEPBible TAGNT (Greek New Testament, CC BY 4.0); the Berean Standard Bible (public domain). Reformatted by Word Study, wording unchanged. All sources and licenses.