Easton's Bible Dictionary (1897)
(1.) A runner, or courier, for the rapid transmission of letters, etc. (2 Chr. 30:6; Esther 3:13, 15; 8:10, 14; Job 9:25; Jer. 51:31). Such messengers were used from very early times. Those employed by the Hebrew kings had a military character (1 Sam. 22:17; 2 Kings 10:25, “guard,” marg. “runners”). The modern system of postal communication was first established by Louis XI. of France in A.D. 1464. (2.) This word sometimes also is used
for lintel or threshold (Isa. 6:4).
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
POST (the Hebrew word means a runner), a messenger or bearer of tidings, especially of royal despatches. Esth 3:13, 2 Sam 20:15; Am 8:14; Jer 51:31. That they were employed in very early times is proved by Job's comparison. Job 9:25. To convey intelligence quickly, the Persian kings placed sentinels at proper distances, who, by crying to one another, gave notices of public occurrences. This method being impracticable for secret intelligence,
Cyrus established posts that rode night and day. Persians and Romans impressed men and beasts into this public service, and to this fact our Lord alludes. Matt 5:41. The regularity and swiftness of the Roman posts were admirable.