The quick answer is that Elohim is plural in syntactic form but singular in
meaning (possibly reflecting an earlier, polytheistic usage). Such forms
are not unusual in Hebrew (cf the words for "water" and "heaven") and other
languages. A rough parallel occurs in English in such words as "scissors"
or "glasses".
For extensive discussion of this topic, please the archives of the b-hebrew
and ioudaios mailing list.
Nichael "Pull down...
nichael@sover.net ...tear up."
http://www.sover.net/~nichael/ -D. Martin