I want you to ask yourself a couple of other questions too. When He said, they would know His voice, how were they suppose to know it if He wasn't around. Abraham and Moses were Hebrews. They knew His voice. In fact Jesus said Abrahams seeds were Christ seed. When He was questioned they asked if He was the King of Jews. He said thou sayest it. He said His kingdom was not of this Word. He is the King of Kings and the Lord of Lords.