Chapter 9 begins under a subsection heading in my Bible, The Government of the Promised Son.
But there is something interesting in Isaiah 9:6 that has puzzled some that I want to address because it is simple to answer when we consider the singular perfect work of the Word under the direction of the Father to accomplish what He and the Father had determined in a very orderly plan.
Isaiah 9:6 gives certain titles of responsibility of the One who would become the promised Messiah.
Jesus Christ, as Jesus Christ of Nazareth, is the promised Son of God, and the government will be on His shoulder. He also fills these titles of Wonderful, Counselor, Mighty God, Everlasting Father, and Prince of Peace.
Christ is all of these things, including Everlasting Father. This may seem to be contrary to Christ's words that no one knew the Father before He came to reveal Him. But this answer should be simple in knowing that the God of the Old Testament is the Word. He is the One with whom all men have dealt from creation. He is the One who is in the process of bringing the whole creation to the end the Father and the Word planned from the beginning.
It is He who has done all the wondrous works of God to be remembered. He is the One who has given birth to the nation of Israel as His special people and will ultimately bring them back to salvation.
Also, in a minute we are going to see that Jeremiah 31:9 also shows that as far as Israel is concerned, it is He that is called a Father to them as He returns and sets up His government.