What does Les say he will show from Hebrews about the Word?
He says he will show from Hebrews that it is the Word, the Son of God, Christ, who has spoken in this book. The Word is the communicator of the Godhead, God the Son. This confirms the speaking person in creation and revelation is God the Son, the communicating member of the triune Godhead.
Les teaches that the Word was with God and was God, and that the triune Godhead was complete and in absolute consensus. Since the word "Word" implies communication, he explains there had to be a person of the Godhead to communicate with creation. He then says that when we get to Hebrews he will show it is the Word, the Son of God, Christ, who has spoken in this book. This is the Word of the very person of the Godhead who is the communicator, God the Son.