Is it farther or further?
"design stamped on wax," especially one attached to a document as evidence of authenticity, c.1200, from Old French seel "seal on a letter" (Modern French sceau), from Vulgar Latin *sigellum (source of Italian suggello, Spanish sello; also Old Frisian and Middle High German sigel, German Siegel), from Latin sigillum "small picture, engraved figure, seal," diminutive of signum "mark, token" (see sign (n.)). An earlier borrowing directly from Latin is represented by Old English insigel. Technical use, "what prevents the escape of a gas or liquid" is from 1853.
fish-eating mammal with flippers, Old English seolh "seal," from Proto-Germanic *selkhaz (cf. Old Norse selr, Swedish sjöl, Danish sæl, Middle Low German sel, Middle Dutch seel, Old High German selah), of unknown origin, perhaps a borrowing from Finnic. Seal point "dark brown marking on a Siamese cat" is recorded from 1934, from the dark brown color of seal fur; cf. seal brown "rich, dark brown color," by 1875. Old English seolhbæð, literally "seal's bath," was an Anglo-Saxon kenning for "the sea."
"to fasten with (or as with) a seal," c.1200, from seal (n.1). Meaning "to place a seal on (a document)" is recorded from mid-14c.; hence "to conclude, ratify, render official" (late 15c.). Sense of "to close up with wax, lead, cement, etc." is attested from 1660s, from the notion of wax seals on envelopes. In reference to the actions of wood-coatings, 1940. Related: Sealed; sealing. Sealing-wax is attested from c.1300. To seal (one's) fate (1799) probably reflects the notion of a seal on an execution warrant.
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.) 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).