I think this is the first mention of a Hebrew. I did a phrase search for the KJV version and this is the first occurence of the word. A Hebrew is only used in the context of foreigners. There is also a dictionary reference to Hebrew in Easton's Bible dictionary if you want to know what are the possible roots of this word:
http://mydevotion.com/logos/ebd/T0001701.html#T0001707