Copyright 1996-2004 Robert Nguyen Cramer
Ebedmelech was a saris, usually translated from the Hebrew as eunuch, but it more accurately means palace official, some of whom were eunuchs. Ebedmelech was a non-Jewish slave from what is modern day northern Sudan -- then called variously Cush, Nubia, or Ethiopia. He was obviously a trusted palace official, but he may or may not have been physically a eunuch.
Jeremiah had been thrown by Jews from Judah into a cistern and left to die, because they accused Jeremiah's practical realism of being demoralizing doom-saying. Jer 38:7-13 describes how Ebedmelech went to Zedekiah, King of Judah, to inform him that Jeremiah needed to be rescued from impending death, whereupon Zedekiah order Ebedmelech to do whatever necessary to rescue Jeremiah.
James Philip Hyatt (The Interpreter's Bible, Volume 5, edited by George Arthur Buttrick, Nashville: Abingdon, 1956) comments on Jer 38:6 (page 1075):
In ancient Jerusalem, as today, there were many cisterns for catching water during the rainy season of the winter, to be stored for use in the vitually rainless months from May to October. At this time there was no water in the cistern, but only mire [mud]. The time was shortly before the Babylonians made a breach in the wall of Jerusalem, August 587 B.C. (52:5-70).
In Jer 39:15-18 Jeremiah articulated God's promise to Ebedmelech.
Harper’s Bible Dictionary
edited by Paul J. Achtemier (San Francisco: Harper and Row, 1985)
You are strongly recommended to add to your library the excellent revised edition of Harper's Bible Dictionary titled, The Harper Collins Bible Dictionary, Revised Edition [book review], edited by Paul J. Achtemeier, with the Society of Biblical Literature (NY: Harper Collins, 1996). It is currently the best one-volume Bible dictionary in English, and it is available at Border's Books, Christian Science Reading Rooms, http://www.borders.com, or http://www.christianbook.com.
Ebedmelech (servant of the king), the Ethiopian eunuch and Jerusalem palace official who was responsible for rescuing Jeremiah out of an empty cistern into which the latter had been thrown by the Judeans, who found offensive Jeremiahs advice to surrender to the Babylonians (Jer. 38:1-13).
Edited for BibleTexts.com by Robert Nguyen Cramer