The Iranian/Farsi name Behin seems to be used in Arabic as well, as Baheen (at least the transliteration is given as thus).
I could not find a good source for a meaning of either name.
What I did find on several sites of unknown quality is a meaning of "best", e.g. here:
http://www.skyscrapercity.com/showthread.php?t=842266
An online Farsi dictionary that I checked did not list a word بهین behin at all, however...
Rene www.BabyNames.ch