First off the word hebrew was an act before it became a language.Abraham who was a chaldean from Ur was observed crossing over the tigris river,moving about from one side to another,this act was called Hebrew,to cross from one side to the other.The other tribes of israel were destroyed,only judah who were a branch from the ishmalites and medianites survived.Today they are called The Falashas and they are called Israel to this day.They live by the Torah and still speak Hebrew and arabic,being they are from the same language,just a different dialect.