Holman Bible Dictionary
(leeb-kuh' mi) Transliteration of Hebrew text. A code name for Babylon (Jeremiah 51:1 , NAS, NIV, NRSV, REB, RSV margin; Kambul, NEB). The code employed is athbash, a code which replaces each letter of a word with a letter that stands as far from the end of the alphabet as the coded letter stands from the beginning (z; y). NAS marginal reading “the heart of those who are against me” arose when the Masoretes added vowels to the code.
Hastings' Dictionary of the Bible
LEB-KAMAI. In Jeremiah 51:1 is a phrase ‘in the midst of them which rise up against me’ (Heb. leb-qamai ). This is generally recognized as being an example of the Kabbalistic rule of hermeneutics whereby a cipher word was obtained by taking the letters of the alphabet in the reverse order, the last for the first, the last but one for the second, and so on. By this process (known as Atbash), leb-qamai gives us Kasdim (the ChaldÃ¦ans).
W. F. Cobb.