Seal

commonly a ring engraved with some device (Gen. 38:18, 25).
Jezebel "wrote letters in Ahab's name, and sealed them with his
seal" (1 Kings 21:8). Seals are frequently mentioned in Jewish
history (Deut. 32:34; Neh. 9:38; 10:1; Esther 3:12; Cant. 8:6;
Isa. 8:16; Jer. 22:24; 32:44, etc.). Sealing a document was
equivalent to the signature of the owner of the seal. "The use
of a signet-ring by the monarch has recently received a
remarkable illustration by the discovery of an impression of
such a signet on fine clay at Koyunjik, the site of the ancient
Nineveh. This seal appears to have been impressed from the bezel
of a metallic finger-ring. It is an oval, 2 inches in length by
1 inch wide, and bears the image, name, and titles of the
Egyptian king Sabaco" (Rawlinson's Hist. Illus. of the O.T., p.
46). The actual signet-rings of two Egyptian kings (Cheops and
Horus) have been discovered. (See SIGNET T0003426.)

The use of seals is mentioned in the New Testament only in
connection with the record of our Lord's burial (Matt. 27:66).
The tomb was sealed by the Pharisees and chief priests for the
purpose of making sure that the disciples would not come and
steal the body away (ver. 63, 64). The mode of doing this was
probably by stretching a cord across the stone and sealing it at
both ends with sealing-clay. When God is said to have sealed the
Redeemer, the meaning is, that he has attested his divine
mission (John 6:27). Circumcision is a seal, an attestation of
the covenant (Rom. 4:11). Believers are sealed with the Spirit,
as God's mark put upon them (Eph. 1:13; 4:30). Converts are by
Paul styled the seal of his apostleship, i.e., they are its
attestation (1 Cor. 9:2). Seals and sealing are frequently
mentioned in the book of Revelation (5:1; 6:1; 7:3; 10:4;
22:10).